http://localhost:5000/
31
Performance
94
Accessibility
87
Best Practices
77
SEO
Progressive Web App
31
Performance
94
Accessibility
87
Best Practices
77
SEO
Progressive Web App
0–49 50–89 90–100
31
Performance
Metrics
First Contentful Paint
6.6 s
First Contentful Paint marks the time at which the first text or image is painted. Learn more.
Speed Index
6.6 s
Speed Index shows how quickly the contents of a page are visibly populated. Learn more.
Largest Contentful Paint
8.7 s
Largest Contentful Paint marks the time at which the largest text or image is painted. Learn more
Time to Interactive
11.9 s
Time to interactive is the amount of time it takes for the page to become fully interactive. Learn more.
Total Blocking Time
860 ms
Sum of all time periods between FCP and Time to Interactive, when task length exceeded 50ms, expressed in milliseconds. Learn more.
Cumulative Layout Shift
0.005
Cumulative Layout Shift measures the movement of visible elements within the viewport. Learn more.
Values are estimated and may vary. The performance score is calculated directly from these metrics.See calculator.
Screenshot
Screenshot
Screenshot
Screenshot
Screenshot
Screenshot
Screenshot
Screenshot
Screenshot
Screenshot
Show audits relevant to:
OpportunitiesThese suggestions can help your page load faster. They don't directly affect the Performance score.
Opportunity
Estimated Savings
Serve images in next-gen formats
12.3 s
Image formats like WebP and AVIF often provide better compression than PNG or JPEG, which means faster downloads and less data consumption. Learn more.
URL
Resource Size
Potential Savings
…case_studies/gravitional.png
(localhost)
748.5 KiB
666.5 KiB
…content_images/ds-landscape.png
(localhost)
475.8 KiB
423.1 KiB
…case_studies/sports.jpg
(localhost)
318.7 KiB
269.9 KiB
…case_studies/deeplabcut.png
(localhost)
278.9 KiB
252.7 KiB
…content_images/data-science.png
(localhost)
183.5 KiB
168.9 KiB
…case_studies/blackhole.png
(localhost)
131.7 KiB
124.7 KiB
…arlib/xarray.png
(localhost)
106.4 KiB
95.8 KiB
…arlib/tensorly.png
(localhost)
97.7 KiB
69.1 KiB
…arlib/sparse.png
(localhost)
76.3 KiB
67.7 KiB
…arlib/cupy.png
(localhost)
64.8 KiB
47.0 KiB
…arlib/xtensor.png
(localhost)
55.0 KiB
41.7 KiB
…arlib/uarray.png
(localhost)
39.8 KiB
34.1 KiB
…content_images/v_vispy.png
(localhost)
37.7 KiB
33.4 KiB
…content_images/v_napari.png
(localhost)
35.0 KiB
31.2 KiB
…arlib/mxnet_logo.png
(localhost)
36.3 KiB
25.8 KiB
…arlib/jax_logo_250px.png
(localhost)
33.2 KiB
25.7 KiB
…content_images/v_pyvista.png
(localhost)
21.2 KiB
19.3 KiB
…content_images/v_matplotlib.png
(localhost)
20.7 KiB
18.3 KiB
…content_images/v_altair.png
(localhost)
18.2 KiB
15.9 KiB
…content_images/v_ggpy.png
(localhost)
16.5 KiB
15.0 KiB
…arlib/dask.png
(localhost)
19.2 KiB
12.6 KiB
…content_images/v_seaborn.png
(localhost)
14.2 KiB
12.4 KiB
…arlib/xnd.png
(localhost)
19.7 KiB
11.3 KiB
…content_images/v_plotly.png
(localhost)
9.9 KiB
9.0 KiB
Eliminate render-blocking resources
5.58 s
Resources are blocking the first paint of your page. Consider delivering critical JS/CSS inline and deferring all non-critical JS/styles. Learn more.FCPLCP
URL
Transfer Size
Potential Savings
/css?family=Lato:400,900
(fonts.googleapis.com)
0.7 KiB
760 ms
…fresh/core.min.8824700….css
(localhost)
3.9 KiB
310 ms
…scientific-python-hugo-theme/bulma.css
(localhost)
0.4 KiB
310 ms
…scientific-python-hugo-theme/vars.css
(localhost)
0.7 KiB
310 ms
…scientific-python-hugo-theme/styles.css
(localhost)
1.6 KiB
310 ms
…scientific-python-hugo-theme/content.css
(localhost)
0.8 KiB
310 ms
…scientific-python-hugo-theme/news.css
(localhost)
1.2 KiB
310 ms
…scientific-python-hugo-theme/keyfeatures.css
(localhost)
1.1 KiB
160 ms
…scientific-python-hugo-theme/tables.css
(localhost)
0.6 KiB
160 ms
…scientific-python-hugo-theme/videos.css
(localhost)
0.8 KiB
160 ms
…scientific-python-hugo-theme/posts.css
(localhost)
0.8 KiB
160 ms
…scientific-python-hugo-theme/teams.css
(localhost)
0.7 KiB
160 ms
…scientific-python-hugo-theme/code-highlight.css
(localhost)
1.3 KiB
160 ms
…user/casestudies.min.62be4a9….css
(localhost)
0.9 KiB
160 ms
…user/mailchimp.min.61f09cb….css
(localhost)
0.8 KiB
160 ms
…user/shell.min.0416e78….css
(localhost)
1.2 KiB
160 ms
…user/tabs.min.9692499….css
(localhost)
1.0 KiB
160 ms
…lib/index.js
(unpkg.com)
578.6 KiB
4,220 ms
Use video formats for animated content
4.8 s
Large GIFs are inefficient for delivering animated content. Consider using MPEG4/WebM videos for animations and PNG/WebP for static images instead of GIF to save network bytes. Learn moreLCP
URL
Resource Size
Potential Savings
…ml_img/tensorflow-ml-anim.gif
(localhost)
1,239.0 KiB
954.0 KiB
Reduce unused JavaScript
4.41 s
Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn more.LCP
URL
Transfer Size
Potential Savings
…lib/index.js
(unpkg.com)
578.6 KiB
349.3 KiB
…./node_modules/codemirror/lib/codemirror.js
39.2 KiB
35.3 KiB
…./node_modules/@lumino/widgets/dist/index.es6.js
37.0 KiB
29.9 KiB
…./node_modules/jquery/dist/jquery.js
20.4 KiB
14.4 KiB
…./node_modules/codemirror/theme/ambiance.css
12.4 KiB
12.4 KiB
…./node_modules/yjs/dist/yjs.mjs
11.2 KiB
11.0 KiB
…js/uikit.min.js
(cdn.jsdelivr.net)
43.3 KiB
30.3 KiB
Efficiently encode images
1.05 s
Optimized images load faster and consume less cellular data. Learn more.
URL
Resource Size
Potential Savings
…case_studies/sports.jpg
(localhost)
318.7 KiB
213.7 KiB
Reduce unused CSS
0.32 s
Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. Learn more.FCPLCP
URL
Transfer Size
Potential Savings
…css/uikit.min.css
(cdn.jsdelivr.net)
30.2 KiB
29.9 KiB
…css/bulma.min.css
(cdn.jsdelivr.net)
28.2 KiB
27.5 KiB
/* Copyright (c) Jupyter Development Team.
 * Distributed under the terms of the Modified BSD Licens...
17.7 KiB
17.1 KiB
…css/all.min.css
(cdnjs.cloudflare.com)
10.6 KiB
10.5 KiB
Preconnect to required origins
0.3 s
Consider adding `preconnect` or `dns-prefetch` resource hints to establish early connections to important third-party origins. Learn more.FCPLCP
URL
Potential Savings
https://fonts.gstatic.com
300 ms
Properly size images
0.3 s
Serve images that are appropriately-sized to save cellular data and improve load time. Learn more.
URL
Resource Size
Potential Savings
…case_studies/gravitional.png
(localhost)
748.5 KiB
21.3 KiB
…content_images/data-science.png
(localhost)
183.5 KiB
16.2 KiB
…case_studies/sports.jpg
(localhost)
318.7 KiB
9.1 KiB
DiagnosticsMore information about the performance of your application. These numbers don't directly affect the Performance score.
Ensure text remains visible during webfont load
Leverage the font-display CSS feature to ensure text is user-visible while webfonts are loading. Learn more.FCPLCP
URL
Potential Savings
…v22/S6u9w4BMU….woff2
(fonts.gstatic.com)
30 ms
…v22/S6uyw4BMU….woff2
(fonts.gstatic.com)
30 ms
Reduce the impact of third-party code Third-party code blocked the main thread for 1,360 ms
Third-party code can significantly impact load performance. Limit the number of redundant third-party providers and try to load third-party code after your page has primarily finished loading. Learn more.TBT
Third-Party
Transfer Size
Main-Thread Blocking Time
Unpkg
579 KiB
1,209 ms
…lib/index.js
(unpkg.com)
579 KiB
1,209 ms
Cloudflare CDN
460 KiB
91 ms
…js/all.min.js
(cdnjs.cloudflare.com)
356 KiB
56 ms
…2.8.3/modernizr.min.js
(cdnjs.cloudflare.com)
5 KiB
35 ms
…webfonts/fa-brands-400.woff2
(cdnjs.cloudflare.com)
76 KiB
0 ms
Other resources
24 KiB
0 ms
Google Analytics
20 KiB
48 ms
/analytics.js
(www.google-analytics.com)
20 KiB
48 ms
JSDelivr CDN
102 KiB
14 ms
…js/uikit.min.js
(cdn.jsdelivr.net)
43 KiB
14 ms
…css/uikit.min.css
(cdn.jsdelivr.net)
30 KiB
0 ms
…css/bulma.min.css
(cdn.jsdelivr.net)
28 KiB
0 ms
jQuery CDN
30 KiB
0 ms
/jquery-3.6.0.min.js
(code.jquery.com)
30 KiB
0 ms
Google Fonts
28 KiB
0 ms
…v22/S6u9w4BMU….woff2
(fonts.gstatic.com)
14 KiB
0 ms
…v22/S6uyw4BMU….woff2
(fonts.gstatic.com)
14 KiB
0 ms
Image elements do not have explicit width and height
Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn moreCLS
URL
Failing Elements
…case_studies/blackhole.png
(localhost)
First image of a black hole. It is an orange circle in a black background.
<img src="/images/content_images/case_studies/blackhole.png" alt="First image of a black hole. It is an orange circle in a black background.">
…case_studies/gravitional.png
(localhost)
Two orbs orbiting each other. They are displacing gravity around them.
<img src="/images/content_images/case_studies/gravitional.png" alt="Two orbs orbiting each other. They are displacing gravity around them.">
…case_studies/sports.jpg
(localhost)
Cricket ball on green field.
<img src="/images/content_images/case_studies/sports.jpg" alt="Cricket ball on green field.">
…case_studies/deeplabcut.png
(localhost)
Cheetah pose analysis
<img src="/images/content_images/case_studies/deeplabcut.png" alt="Cheetah pose analysis">
/images/logo.svg
(localhost)
NumPy logo
<img id="navbar-logo" src="/images/logo.svg" alt="NumPy logo">
/images/logo.svg
(localhost)
NumPy logo.
<img class="hero-logo" src="/images/logo.svg" alt="NumPy logo. ">
/images/logo.svg
(localhost)
NumPy logo.
<img id="footer-logo" src="/images/logo.svg" alt="NumPy logo. ">
Avoid enormous network payloads Total size was 5,398 KiB
Large network payloads cost users real money and are highly correlated with long load times. Learn more.LCP
URL
Transfer Size
…ml_img/tensorflow-ml-anim.gif
(localhost)
1,239.3 KiB
…case_studies/gravitional.png
(localhost)
748.8 KiB
…lib/index.js
(unpkg.com)
578.6 KiB
…content_images/ds-landscape.png
(localhost)
476.1 KiB
…js/all.min.js
(cdnjs.cloudflare.com)
356.0 KiB
…case_studies/sports.jpg
(localhost)
319.0 KiB
…case_studies/deeplabcut.png
(localhost)
279.2 KiB
…content_images/data-science.png
(localhost)
183.8 KiB
…case_studies/blackhole.png
(localhost)
132.0 KiB
…arlib/xarray.png
(localhost)
106.7 KiB
Minimize main-thread work 4.6 s
Consider reducing the time spent parsing, compiling and executing JS. You may find delivering smaller JS payloads helps with this. Learn moreTBT
Category
Time Spent
Script Evaluation
1,502 ms
Style & Layout
1,243 ms
Other
1,101 ms
Script Parsing & Compilation
311 ms
Parse HTML & CSS
248 ms
Rendering
167 ms
Garbage Collection
31 ms
Reduce JavaScript execution time 1.8 s
Consider reducing the time spent parsing, compiling, and executing JS. You may find delivering smaller JS payloads helps with this. Learn more.TBT
URL
Total CPU Time
Script Evaluation
Script Parse
http://localhost:5000
1,398 ms
43 ms
5 ms
…lib/index.js
(unpkg.com)
1,392 ms
984 ms
198 ms
Unattributable
721 ms
16 ms
1 ms
…js/all.min.js
(cdnjs.cloudflare.com)
306 ms
66 ms
62 ms
…js/uikit.min.js
(cdn.jsdelivr.net)
217 ms
116 ms
8 ms
/analytics.js
(www.google-analytics.com)
203 ms
100 ms
26 ms
…2.8.3/modernizr.min.js
(cdnjs.cloudflare.com)
123 ms
90 ms
1 ms
/jquery-3.6.0.min.js
(code.jquery.com)
117 ms
75 ms
7 ms
Avoid chaining critical requests 29 chains found
The Critical Request Chains below show you what resources are loaded with a high priority. Consider reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load. Learn more.FCPLCP
Maximum critical path latency: 1,350 ms
Initial Navigation
http://localhost:5000
/css?family=Lato:400,900
(fonts.googleapis.com)
…v22/S6u9w4BMU….woff2
(fonts.gstatic.com)
- 30 ms, 13.91 KiB
…v22/S6uyw4BMU….woff2
(fonts.gstatic.com)
- 30 ms, 13.77 KiB
…fresh/core.min.8824700….css
(localhost)
- 20 ms, 3.86 KiB
…scientific-python-hugo-theme/bulma.css
(localhost)
…css/bulma.min.css
(cdn.jsdelivr.net)
- 100 ms, 28.18 KiB
…scientific-python-hugo-theme/vars.css
(localhost)
- 20 ms, 0.72 KiB
…scientific-python-hugo-theme/styles.css
(localhost)
- 20 ms, 1.58 KiB
…scientific-python-hugo-theme/content.css
(localhost)
- 20 ms, 0.82 KiB
…scientific-python-hugo-theme/news.css
(localhost)
- 20 ms, 1.17 KiB
…scientific-python-hugo-theme/keyfeatures.css
(localhost)
- 60 ms, 1.12 KiB
…scientific-python-hugo-theme/tables.css
(localhost)
- 50 ms, 0.55 KiB
…scientific-python-hugo-theme/videos.css
(localhost)
- 60 ms, 0.78 KiB
…scientific-python-hugo-theme/posts.css
(localhost)
- 50 ms, 0.79 KiB
…scientific-python-hugo-theme/teams.css
(localhost)
- 50 ms, 0.75 KiB
…scientific-python-hugo-theme/code-highlight.css
(localhost)
- 50 ms, 1.33 KiB
…user/casestudies.min.62be4a9….css
(localhost)
- 60 ms, 0.94 KiB
…user/mailchimp.min.61f09cb….css
(localhost)
- 100 ms, 0.82 KiB
…user/shell.min.0416e78….css
(localhost)
- 70 ms, 1.21 KiB
…user/tabs.min.9692499….css
(localhost)
- 70 ms, 1.04 KiB
…css/all.min.css
(cdnjs.cloudflare.com)
…webfonts/fa-brands-400.woff2
(cdnjs.cloudflare.com)
- 80 ms, 75.63 KiB
…webfonts/fa-regular-400.woff2
(cdnjs.cloudflare.com)
- 50 ms, 13.62 KiB
…css/uikit.min.css
(cdn.jsdelivr.net)
- 70 ms, 30.19 KiB
…lib/index.js
(unpkg.com)
- 200 ms, 578.63 KiB
/jquery-3.6.0.min.js
(code.jquery.com)
- 60 ms, 30.40 KiB
/js/fresh.js
(localhost)
- 20 ms, 1.73 KiB
…2.8.3/modernizr.min.js
(cdnjs.cloudflare.com)
- 80 ms, 4.63 KiB
…js/all.min.js
(cdnjs.cloudflare.com)
- 370 ms, 356.02 KiB
…js/uikit.min.js
(cdn.jsdelivr.net)
- 50 ms, 43.35 KiB
/js/shortcuts.js
(localhost)
- 30 ms, 1.02 KiB
/js/app.js
(localhost)
- 30 ms, 1.30 KiB
Keep request counts low and transfer sizes small 80 requests • 5,398 KiB
To set budgets for the quantity and size of page resources, add a budget.json file. Learn more.
Resource Type
Requests
Transfer Size
Total
80
5,398.0 KiB
Image
44
4,144.5 KiB
Script
10
1,037.8 KiB
Font
4
116.9 KiB
Stylesheet
20
87.6 KiB
Document
1
11.0 KiB
Other
1
0.2 KiB
Media
0
0.0 KiB
Third-party
17
1,220.7 KiB
Largest Contentful Paint element 1 element found
This is the largest contentful element painted within the viewport. Learn MoreLCP
Element
Fast and versatile, the NumPy vectorization, indexing, and broadcasting concept…
<div class="keyfeatures-box-text">
Avoid large layout shifts 3 elements found
These DOM elements contribute most to the CLS of the page.CLS
Element
CLS Contribution
NumPy
<div class="hero-title">
0.004
POWERFUL N-DIMENSIONAL ARRAYS
<div class="keyfeatures-box-title">
0
Fast and versatile, the NumPy vectorization, indexing, and broadcasting concept…
<div class="keyfeatures-box-text">
0
Avoid long main-thread tasks 9 long tasks found
Lists the longest tasks on the main thread, useful for identifying worst contributors to input delay. Learn moreTBT
URL
Start Time
Duration
…lib/index.js
(unpkg.com)
11,694 ms
1,425 ms
http://localhost:5000
685 ms
399 ms
…js/all.min.js
(cdnjs.cloudflare.com)
13,119 ms
231 ms
…js/uikit.min.js
(cdn.jsdelivr.net)
8,710 ms
136 ms
/analytics.js
(www.google-analytics.com)
2,193 ms
80 ms
http://localhost:5000
607 ms
78 ms
Unattributable
1,151 ms
77 ms
…2.8.3/modernizr.min.js
(cdnjs.cloudflare.com)
1,637 ms
62 ms
/jquery-3.6.0.min.js
(code.jquery.com)
2,756 ms
54 ms
Avoid non-composited animations 1 animated element found
Animations which are not composited can be janky and increase CLS. Learn moreCLS
Element
Name
SCIENTIFIC DOMAINS
<a href="#">
Unsupported CSS Property: color
color
Passed audits (19)
Defer offscreen images Potential savings of 472 KiB
Consider lazy-loading offscreen and hidden images after all critical resources have finished loading to lower time to interactive. Learn more.
URL
Resource Size
Potential Savings
…arlib/xarray.png
(localhost)
106.4 KiB
106.4 KiB
…arlib/sparse.png
(localhost)
76.3 KiB
76.3 KiB
…arlib/cupy.png
(localhost)
64.8 KiB
64.8 KiB
…arlib/xtensor.png
(localhost)
55.0 KiB
55.0 KiB
…arlib/uarray.png
(localhost)
39.8 KiB
39.8 KiB
…arlib/mxnet_logo.png
(localhost)
36.3 KiB
36.3 KiB
…arlib/jax_logo_250px.png
(localhost)
33.2 KiB
33.2 KiB
…arlib/arrow.png
(localhost)
21.1 KiB
21.1 KiB
…arlib/xnd.png
(localhost)
19.7 KiB
19.7 KiB
…arlib/dask.png
(localhost)
19.2 KiB
19.2 KiB
Minify CSS Potential savings of 44 KiB
Minifying CSS files can reduce network payload sizes. Learn more.FCPLCP
URL
Transfer Size
Potential Savings
/* Copyright (c) Jupyter Development Team.
 * Distributed under the terms of the Modified BSD Licens...
17.7 KiB
12.8 KiB
/*-----------------------------------------------------------------------------
| Copyright (c) Jupy...
7.5 KiB
5.9 KiB
/*-----------------------------------------------------------------------------
| Copyright (c) Jupy...
7.9 KiB
5.6 KiB
/* BASICS */

.CodeMirror {
  /* Set height, width, borders, and global font properties here */
  fo... } ...
5.1 KiB
3.9 KiB
/**
 * The material design colors are adapted from google-material-color v1.2.6
 * https://github.co...
5.0 KiB
3.8 KiB
/*-----------------------------------------------------------------------------
| Copyright (c) Jupy...
3.9 KiB
3.1 KiB
/**
 * google-material-color v1.2.6
 * https://github.com/danlevan/google-material-color
 */
:root {...
4.3 KiB
3.1 KiB
/*-----------------------------------------------------------------------------
| Copyright (c) Jupy...
3.9 KiB
2.9 KiB
/*-----------------------------------------------------------------------------
| Copyright (c) Jupy...
3.4 KiB
2.6 KiB
Minify JavaScript
Minifying JavaScript files can reduce payload sizes and script parse time. Learn more.FCPLCP
Enable text compression
Text-based resources should be served with compression (gzip, deflate or brotli) to minimize total network bytes. Learn more.FCPLCP
Initial server response time was short Root document took 10 ms
Keep the server response time for the main document short because all other requests depend on it. Learn more.FCPLCP
URL
Time Spent
http://localhost:5000
10 ms
Avoid multiple page redirects
Redirects introduce additional delays before the page can be loaded. Learn more.FCPLCP
Preload key requests
Consider using `<link rel=preload>` to prioritize fetching resources that are currently requested later in page load. Learn more.FCPLCP
Use HTTP/2
HTTP/2 offers many benefits over HTTP/1.1, including binary headers and multiplexing. Learn more.
Remove duplicate modules in JavaScript bundles
Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity. TBT
Avoid serving legacy JavaScript to modern browsers Potential savings of 8 KiB
Polyfills and transforms enable legacy browsers to use new JavaScript features. However, many aren't necessary for modern browsers. For your bundled JavaScript, adopt a modern script deployment strategy using module/nomodule feature detection to reduce the amount of code shipped to modern browsers, while retaining support for legacy browsers. Learn MoreTBT
URL
Potential Savings
…lib/index.js
(unpkg.com)
7.5 KiB
webpack:///./node_modules/core-js/modules/es.array.map.js:11:2
Array.prototype.map
webpack:///./node_modules/resize-observer-polyfill/dist/ResizeObserver.es.js:897:32
@babel/plugin-transform-classes
webpack:///./node_modules/core-js/modules/es.array.filter.js:11:2
Array.prototype.filter
webpack:///./node_modules/core-js/modules/es.array.find.js:14:2
Array.prototype.find
webpack:///./src/manager.js:60:13
@babel/plugin-transform-regenerator
…js/all.min.js
(cdnjs.cloudflare.com)
0.0 KiB
…js/all.min.js:5:1191683
(cdnjs.cloudflare.com)
@babel/plugin-transform-classes
Preload Largest Contentful Paint image
Preload the image used by the LCP element in order to improve your LCP time. Learn more.LCP
Uses efficient cache policy on static assets 1 resource found
A long cache lifetime can speed up repeat visits to your page. Learn more.
URL
Cache TTL
Transfer Size
/analytics.js
(www.google-analytics.com)
2 h
20 KiB
Avoids an excessive DOM size 671 elements
A large DOM will increase memory usage, cause longer style calculations, and produce costly layout reflows. Learn more.TBT
Statistic
Element
Value
Total DOM Elements
671
Maximum DOM Depth
A streamplot made in matplotlib
<img src="/images/content_images/v_matplotlib.png" alt="A streamplot made in matplotlib" align="middle">
12
Maximum Child Elements
>>> # The standard way to import NumPy: >>> import numpy as np >>> # Create a …
<code class="language-python" data-lang="python">
64
User Timing marks and measures
Consider instrumenting your app with the User Timing API to measure your app's real-world performance during key user experiences. Learn more.
Lazy load third-party resources with facades
Some third-party embeds can be lazy loaded. Consider replacing them with a facade until they are required. Learn more.TBT
Largest Contentful Paint image was not lazily loaded
Above-the-fold images that are lazily loaded render later in the page lifecycle, which can delay the largest contentful paint. Learn more.
Uses passive listeners to improve scrolling performance
Consider marking your touch and wheel event listeners as `passive` to improve your page's scroll performance. Learn more.
Avoids document.write()
For users on slow connections, external scripts dynamically injected via `document.write()` can delay page load by tens of seconds. Learn more.
Has a <meta name="viewport"> tag with width or initial-scale
A `<meta name="viewport">` not only optimizes your app for mobile screen sizes, but also prevents a 300 millisecond delay to user input. Learn more.TBT
94
Accessibility
These checks highlight opportunities to improve the accessibility of your web app. Only a subset of accessibility issues can be automatically detected so manual testing is also encouraged.
ContrastThese are opportunities to improve the legibility of your content.
Background and foreground colors do not have a sufficient contrast ratio.
Low-contrast text is difficult or impossible for many users to read. Learn more.
Failing Elements
ARRAY LIBRARIES
<a href="#">
DATA SCIENCE
<a href="#">
MACHINE LEARNING
<a href="#">
VISUALIZATION
<a href="#">
QuTiP
<a href="http://qutip.org">
Pandas
<a href="https://pandas.pydata.org">
SciPy
<a href="https://www.scipy.org">
Scikit-image
<a href="https://scikit-image.org">
NetworkX
<a href="https://networkx.org">
AstroPy
<a href="https://www.astropy.org">
PsychoPy
<a href="https://www.psychopy.org">
PyQuil
<a href="https://pyquil-docs.rigetti.com/en/stable">
statsmodels
<a href="https://github.com/statsmodels/statsmodels">
PyWavelets
<a href="https://pywavelets.readthedocs.io">
OpenCV
<a href="https://opencv.org">
graph-tool
<a href="https://graph-tool.skewed.de/">
SunPy
<a href="https://github.com/sunpy/sunpy">
Qiskit
<a href="https://qiskit.org">
Xarray
<a href="https://xarray.pydata.org/en/stable/">
python-control
<a href="https://python-control.org">
Mahotas
<a href="https://mahotas.rtfd.io/">
igraph
<a href="https://igraph.org/python/">
SpacePy
<a href="https://github.com/spacepy/spacepy">
Seaborn
<a href="https://github.com/mwaskom/seaborn">
PyGSP
<a href="https://pygsp.rtfd.io">
BioPython
<a href="https://biopython.org">
PyStan
<a href="https://pystan.readthedocs.io/en/latest/">
SciPy
<a href="https://www.scipy.org">
Cantera
<a href="https://cantera.org/">
Pangeo
<a href="https://pangeo.io/">
Shapely
<a href="https://shapely.readthedocs.io">
COMPAS
<a href="https://compas.dev/">
Scikit-Bio
<a href="http://scikit-bio.org">
PyMC3
<a href="https://docs.pymc.io">
SymPy
<a href="https://www.sympy.org">
MDAnalysis
<a href="https://www.mdanalysis.org/">
Simpeg
<a href="https://simpeg.xyz/">
GeoPandas
<a href="https://geopandas.org/">
City Energy Analyst
<a href="https://cityenergyanalyst.com/">
PyEnsembl
<a href="https://github.com/openvax/pyensembl">
ArviZ
<a href="https://arviz-devs.github.io/arviz/">
cvxpy
<a href="https://github.com/cvxgrp/cvxpy">
RDKit
<a href="https://github.com/rdkit/rdkit">
ObsPy
<a href="https://github.com/obspy/obspy/wiki">
Folium
<a href="https://python-visualization.github.io/folium">
Sverchok
<a href="https://nortikin.github.io/sverchok/">
ETE
<a href="http://etetoolkit.org/">
emcee
<a href="https://emcee.readthedocs.io/">
FEniCS
<a href="https://fenicsproject.org/">
Fatiando a Terra
<a href="https://www.fatiando.org/">
NavigationThese are opportunities to improve keyboard navigation in your application.
[id] attributes on active, focusable elements are not unique
All focusable elements must have a unique `id` to ensure that they're visible to assistive technologies. Learn more.
Failing Elements
Install
<a href="/install" id="navbar-item" class="navbar-item is-secondary">
Names and labelsThese are opportunities to improve the semantics of the controls in your application. This may enhance the experience for users of assistive technology, like a screen reader.
Links do not have a discernible name
Link text (and alternate text for images, when used as links) that is discernible, unique, and focusable improves the navigation experience for screen reader users. Learn more.
Failing Elements
body > div#backtotop > a#backtotop-color
<a href="#" id="backtotop-color">
Additional items to manually check (10) These items address areas which an automated testing tool cannot cover. Learn more in our guide on conducting an accessibility review.
The page has a logical tab order
Tabbing through the page follows the visual layout. Users cannot focus elements that are offscreen. Learn more.
Interactive controls are keyboard focusable
Custom interactive controls are keyboard focusable and display a focus indicator. Learn more.
Interactive elements indicate their purpose and state
Interactive elements, such as links and buttons, should indicate their state and be distinguishable from non-interactive elements. Learn more.
The user's focus is directed to new content added to the page
If new content, such as a dialog, is added to the page, the user's focus is directed to it. Learn more.
User focus is not accidentally trapped in a region
A user can tab into and out of any control or region without accidentally trapping their focus. Learn more.
Custom controls have associated labels
Custom interactive controls have associated labels, provided by aria-label or aria-labelledby. Learn more.
Custom controls have ARIA roles
Custom interactive controls have appropriate ARIA roles. Learn more.
Visual order on the page follows DOM order
DOM order matches the visual order, improving navigation for assistive technology. Learn more.
Offscreen content is hidden from assistive technology
Offscreen content is hidden with display: none or aria-hidden=true. Learn more.
HTML5 landmark elements are used to improve navigation
Landmark elements (<main>, <nav>, etc.) are used to improve the keyboard navigation of the page for assistive technology. Learn more.
Passed audits (21)
[aria-*] attributes match their roles
Each ARIA `role` supports a specific subset of `aria-*` attributes. Mismatching these invalidates the `aria-*` attributes. Learn more.
button, link, and menuitem elements have accessible names
When an element doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers. Learn more.
[aria-hidden="true"] is not present on the document <body>
Assistive technologies, like screen readers, work inconsistently when `aria-hidden="true"` is set on the document `<body>`. Learn more.
[aria-hidden="true"] elements do not contain focusable descendents
Focusable descendents within an `[aria-hidden="true"]` element prevent those interactive elements from being available to users of assistive technologies like screen readers. Learn more.
[role]s have all required [aria-*] attributes
Some ARIA roles have required attributes that describe the state of the element to screen readers. Learn more.
[role] values are valid
ARIA roles must have valid values in order to perform their intended accessibility functions. Learn more.
[aria-*] attributes have valid values
Assistive technologies, like screen readers, can't interpret ARIA attributes with invalid values. Learn more.
[aria-*] attributes are valid and not misspelled
Assistive technologies, like screen readers, can't interpret ARIA attributes with invalid names. Learn more.
Buttons have an accessible name
When a button doesn't have an accessible name, screen readers announce it as "button", making it unusable for users who rely on screen readers. Learn more.
The page contains a heading, skip link, or landmark region
Adding ways to bypass repetitive content lets keyboard users navigate the page more efficiently. Learn more.
Document has a <title> element
The title gives screen reader users an overview of the page, and search engine users rely on it heavily to determine if a page is relevant to their search. Learn more.
Heading elements appear in a sequentially-descending order
Properly ordered headings that do not skip levels convey the semantic structure of the page, making it easier to navigate and understand when using assistive technologies. Learn more.
<html> element has a [lang] attribute
If a page doesn't specify a lang attribute, a screen reader assumes that the page is in the default language that the user chose when setting up the screen reader. If the page isn't actually in the default language, then the screen reader might not announce the page's text correctly. Learn more.
<html> element has a valid value for its [lang] attribute
Specifying a valid BCP 47 language helps screen readers announce text properly. Learn more.
Image elements have [alt] attributes
Informative elements should aim for short, descriptive alternate text. Decorative elements can be ignored with an empty alt attribute. Learn more.
Form elements have associated labels
Labels ensure that form controls are announced properly by assistive technologies, like screen readers. Learn more.
Lists contain only <li> elements and script supporting elements (<script> and <template>).
Screen readers have a specific way of announcing lists. Ensuring proper list structure aids screen reader output. Learn more.
List items (<li>) are contained within <ul> or <ol> parent elements
Screen readers require list items (`<li>`) to be contained within a parent `<ul>` or `<ol>` to be announced properly. Learn more.
[user-scalable="no"] is not used in the <meta name="viewport"> element and the [maximum-scale] attribute is not less than 5.
Disabling zooming is problematic for users with low vision who rely on screen magnification to properly see the contents of a web page. Learn more.
Cells in a <table> element that use the [headers] attribute refer to table cells within the same table.
Screen readers have features to make navigating tables easier. Ensuring `<td>` cells using the `[headers]` attribute only refer to other cells in the same table may improve the experience for screen reader users. Learn more.
<th> elements and elements with [role="columnheader"/"rowheader"] have data cells they describe.
Screen readers have features to make navigating tables easier. Ensuring table headers always refer to some set of cells may improve the experience for screen reader users. Learn more.
Not applicable (20)
[accesskey] values are unique
Access keys let users quickly focus a part of the page. For proper navigation, each access key must be unique. Learn more.
ARIA input fields have accessible names
When an input field doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers. Learn more.
ARIA meter elements have accessible names
When an element doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers. Learn more.
ARIA progressbar elements have accessible names
When a `progressbar` element doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers. Learn more.
Elements with an ARIA [role] that require children to contain a specific [role] have all required children.
Some ARIA parent roles must contain specific child roles to perform their intended accessibility functions. Learn more.
[role]s are contained by their required parent element
Some ARIA child roles must be contained by specific parent roles to properly perform their intended accessibility functions. Learn more.
ARIA toggle fields have accessible names
When a toggle field doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers. Learn more.
ARIA tooltip elements have accessible names
When an element doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers. Learn more.
ARIA treeitem elements have accessible names
When an element doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers. Learn more.
<dl>'s contain only properly-ordered <dt> and <dd> groups, <script>, <template> or <div> elements.
When definition lists are not properly marked up, screen readers may produce confusing or inaccurate output. Learn more.
Definition list items are wrapped in <dl> elements
Definition list items (`<dt>` and `<dd>`) must be wrapped in a parent `<dl>` element to ensure that screen readers can properly announce them. Learn more.
ARIA IDs are unique
The value of an ARIA ID must be unique to prevent other instances from being overlooked by assistive technologies. Learn more.
No form fields have multiple labels
Form fields with multiple labels can be confusingly announced by assistive technologies like screen readers which use either the first, the last, or all of the labels. Learn more.
<frame> or <iframe> elements have a title
Screen reader users rely on frame titles to describe the contents of frames. Learn more.
<input type="image"> elements have [alt] text
When an image is being used as an `<input>` button, providing alternative text can help screen reader users understand the purpose of the button. Learn more.
The document does not use <meta http-equiv="refresh">
Users do not expect a page to refresh automatically, and doing so will move focus back to the top of the page. This may create a frustrating or confusing experience. Learn more.
<object> elements have [alt] text
Screen readers cannot translate non-text content. Adding alt text to `<object>` elements helps screen readers convey meaning to users. Learn more.
No element has a [tabindex] value greater than 0
A value greater than 0 implies an explicit navigation ordering. Although technically valid, this often creates frustrating experiences for users who rely on assistive technologies. Learn more.
[lang] attributes have a valid value
Specifying a valid BCP 47 language on elements helps ensure that text is pronounced correctly by a screen reader. Learn more.
<video> elements contain a <track> element with [kind="captions"]
When a video provides a caption it is easier for deaf and hearing impaired users to access its information. Learn more.
87
Best Practices
Trust and Safety
Links to cross-origin destinations are unsafe
Add `rel="noopener"` or `rel="noreferrer"` to any external links to improve performance and prevent security vulnerabilities. Learn more.
Failing Anchors
Help us to translate
<a href="https://crowdin.com/project/numpyorg" id="navbar-item" class="navbar-item" target="_blank">
Help us to translate
<a href="https://crowdin.com/project/numpyorg" id="navbar-item" class="navbar-item" target="_blank">
docs
<a href="https://numpy.org/doc/stable" target="_blank">
Ensure CSP is effective against XSS attacks
A strong Content Security Policy (CSP) significantly reduces the risk of cross-site scripting (XSS) attacks. Learn more
Description
Directive
Severity
No CSP found in enforcement mode
High
User Experience
Displays images with incorrect aspect ratio
Image display dimensions should match natural aspect ratio. Learn more.
URL
Aspect Ratio (Displayed)
Aspect Ratio (Actual)
…content_images/data-science.png
(localhost)
75 x 457 (0.16)
567 x 457 (1.24)
General
Detected JavaScript libraries
All front-end JavaScript libraries detected on the page. Learn more.
Name
Version
jQuery
3.6.0
Modernizr
2.8.3
Backbone
1.2.3
core-js
core-js-global@3.15.2
Passed audits (14)
Uses HTTPS
All sites should be protected with HTTPS, even ones that don't handle sensitive data. This includes avoiding mixed content, where some resources are loaded over HTTP despite the initial request being served over HTTPS. HTTPS prevents intruders from tampering with or passively listening in on the communications between your app and your users, and is a prerequisite for HTTP/2 and many new web platform APIs. Learn more.
Avoids requesting the geolocation permission on page load
Users are mistrustful of or confused by sites that request their location without context. Consider tying the request to a user action instead. Learn more.
Avoids requesting the notification permission on page load
Users are mistrustful of or confused by sites that request to send notifications without context. Consider tying the request to user gestures instead. Learn more.
Avoids front-end JavaScript libraries with known security vulnerabilities
Some third-party scripts may contain known security vulnerabilities that are easily identified and exploited by attackers. Learn more.
Allows users to paste into password fields
Preventing password pasting undermines good security policy. Learn more.
Serves images with appropriate resolution
Image natural dimensions should be proportional to the display size and the pixel ratio to maximize image clarity. Learn more.
Page has the HTML doctype
Specifying a doctype prevents the browser from switching to quirks-mode. Learn more.
Properly defines charset
A character encoding declaration is required. It can be done with a `<meta>` tag in the first 1024 bytes of the HTML or in the Content-Type HTTP response header. Learn more.
Avoids unload event listeners
The `unload` event does not fire reliably and listening for it can prevent browser optimizations like the Back-Forward Cache. Consider using the `pagehide` or `visibilitychange` events instead. Learn more
Avoids Application Cache
Application Cache is deprecated. Learn more.
Avoids deprecated APIs
Deprecated APIs will eventually be removed from the browser. Learn more.
No browser errors logged to the console
Errors logged to the console indicate unresolved problems. They can come from network request failures and other browser concerns. Learn more
Page has valid source maps
Source maps translate minified code to the original source code. This helps developers debug in production. In addition, Lighthouse is able to provide further insights. Consider deploying source maps to take advantage of these benefits. Learn more.
URL
Map URL
…lib/index.js
(unpkg.com)
…lib/index.js.map
(unpkg.com)
No issues in the Issues panel in Chrome Devtools
Issues logged to the `Issues` panel in Chrome Devtools indicate unresolved problems. They can come from network request failures, insufficient security controls, and other browser concerns. Open up the Issues panel in Chrome DevTools for more details on each issue.
Not applicable (1)
Fonts with font-display: optional are preloaded
Preload `optional` fonts so first-time visitors may use them. Learn more
77
SEO
These checks ensure that your page is following basic search engine optimization advice. There are many additional factors Lighthouse does not score here that may affect your search ranking, including performance on Core Web Vitals. Learn more.
Crawling and IndexingTo appear in search results, crawlers need access to your app.
Links are not crawlable
Search engines may use `href` attributes on links to crawl websites. Ensure that the `href` attribute of anchor elements links to an appropriate destination, so more pages of the site can be discovered. Learn More
Uncrawlable Link
English
<a aria-label="Select language" class="navbar-link">
English
<a class="navbar-link">
Content Best PracticesFormat your HTML in a way that enables crawlers to better understand your app’s content.
Document doesn't have a valid hreflang
hreflang links tell search engines what version of a page they should list in search results for a given language or region. Learn more.
head > link
<link rel="alternate" hreflang="pt" href="/pt/" />
Relative href value
head > link
<link rel="alternate" hreflang="ja" href="/ja/" />
Relative href value
Mobile FriendlyMake sure your pages are mobile friendly so users don’t have to pinch or zoom in order to read the content pages. Learn more.
Tap targets are not sized appropriately 24% appropriately sized tap targets
Interactive elements like buttons and links should be large enough (48x48px), and have enough space around them, to be easy enough to tap without overlapping onto other elements. Learn more.
Tap Target
Size
Overlapping Target
SunPy
<a href="https://github.com/sunpy/sunpy">
36x16
SpacePy
<a href="https://github.com/spacepy/spacepy">
igraph
<a href="https://igraph.org/python/">
36x16
graph-tool
<a href="https://graph-tool.skewed.de/">
ETE
<a href="http://etetoolkit.org/">
24x16
PyEnsembl
<a href="https://github.com/openvax/pyensembl">
Qiskit
<a href="https://qiskit.org">
34x16
PyQuil
<a href="https://pyquil-docs.rigetti.com/en/stable">
Xarray
<a href="https://xarray.pydata.org/en/stable/">
39x16
statsmodels
<a href="https://github.com/statsmodels/statsmodels">
OpenCV
<a href="https://opencv.org">
49x16
Mahotas
<a href="https://mahotas.rtfd.io/">
SciPy
<a href="https://www.scipy.org">
31x16
PyWavelets
<a href="https://pywavelets.readthedocs.io">
SciPy
<a href="https://www.scipy.org">
31x16
SymPy
<a href="https://www.sympy.org">
cvxpy
<a href="https://github.com/cvxgrp/cvxpy">
34x16
FEniCS
<a href="https://fenicsproject.org/">
ArviZ
<a href="https://arviz-devs.github.io/arviz/">
32x16
emcee
<a href="https://emcee.readthedocs.io/">
SunPy
<a href="https://github.com/sunpy/sunpy">
36x16
AstroPy
<a href="https://www.astropy.org">
ObsPy
<a href="https://github.com/obspy/obspy/wiki">
38x16
Fatiando a Terra
<a href="https://www.fatiando.org/">
Xarray
<a href="https://xarray.pydata.org/en/stable/">
39x16
Seaborn
<a href="https://github.com/mwaskom/seaborn">
igraph
<a href="https://igraph.org/python/">
36x16
PyGSP
<a href="https://pygsp.rtfd.io">
Scikit-image
<a href="https://scikit-image.org">
36x16
OpenCV
<a href="https://opencv.org">
PyStan
<a href="https://pystan.readthedocs.io/en/latest/">
41x16
PyMC3
<a href="https://docs.pymc.io">
Pandas
<a href="https://pandas.pydata.org">
42x16
statsmodels
<a href="https://github.com/statsmodels/statsmodels">
QuTiP
<a href="http://qutip.org">
36x16
PyQuil
<a href="https://pyquil-docs.rigetti.com/en/stable">
Shapely
<a href="https://shapely.readthedocs.io">
45x16
GeoPandas
<a href="https://geopandas.org/">
Simpeg
<a href="https://simpeg.xyz/">
42x16
Pangeo
<a href="https://pangeo.io/">
Cantera
<a href="https://cantera.org/">
47x16
MDAnalysis
<a href="https://www.mdanalysis.org/">
NetworkX
<a href="https://networkx.org">
59x16
graph-tool
<a href="https://graph-tool.skewed.de/">
BioPython
<a href="https://biopython.org">
59x16
Scikit-Bio
<a href="http://scikit-bio.org">
COMPAS
<a href="https://compas.dev/">
54x16
City Energy Analyst
<a href="https://cityenergyanalyst.com/">
python-control
<a href="https://python-control.org">
45x16
PyWavelets
<a href="https://pywavelets.readthedocs.io">
Sverchok
<a href="https://nortikin.github.io/sverchok/">
53x16
City Energy Analyst
<a href="https://cityenergyanalyst.com/">
ArviZ
<a href="https://arviz-devs.github.io/arviz/">
32x16
PyMC3
<a href="https://docs.pymc.io">
Learn
<a class="footer-link" href="/learn">
39x19
Documentation
<a class="footer-link" href="https://numpy.org/doc/stable">
Learn
<a class="footer-link" href="/learn">
39x19
Citing Numpy
<a class="footer-link" href="/citing-numpy">
RDKit
<a href="https://github.com/rdkit/rdkit">
35x16
MDAnalysis
<a href="https://www.mdanalysis.org/">
cvxpy
<a href="https://github.com/cvxgrp/cvxpy">
34x16
SymPy
<a href="https://www.sympy.org">
Folium
<a href="https://python-visualization.github.io/folium">
38x16
GeoPandas
<a href="https://geopandas.org/">
Install
<a class="footer-link" href="/install">
43x19
Documentation
<a class="footer-link" href="https://numpy.org/doc/stable">
ObsPy
<a href="https://github.com/obspy/obspy/wiki">
38x16
Simpeg
<a href="https://simpeg.xyz/">
Scikit-Bio
<a href="http://scikit-bio.org">
54x16
PyEnsembl
<a href="https://github.com/openvax/pyensembl">
Citing Numpy
<a class="footer-link" href="/citing-numpy">
96x19
Roadmap
<a class="footer-link" href="https://numpy.org/neps/roadmap.html">
About us
<a class="footer-link" href="/about">
63x19
Community
<a class="footer-link" href="/community">
Community
<a class="footer-link" href="/community">
82x19
User surveys
<a class="footer-link" href="/user-surveys">
User surveys
<a class="footer-link" href="/user-surveys">
89x19
Contribute
<a class="footer-link" href="/contribute">
Contribute
<a class="footer-link" href="/contribute">
77x19
Code of conduct
<a class="footer-link" href="/code-of-conduct">
Get help
<a class="footer-link" href="/gethelp">
59x19
Terms of use
<a class="footer-link" href="/terms">
Terms of use
<a class="footer-link" href="/terms">
85x19
Privacy
<a class="footer-link" href="/privacy">
Privacy
<a class="footer-link" href="/privacy">
51x19
Press kit
<a class="footer-link" href="/press-kit">
Additional items to manually check (1) Run these additional validators on your site to check additional SEO best practices.
Structured data is valid
Run the Structured Data Testing Tool and the Structured Data Linter to validate structured data. Learn more.
Passed audits (9)
Has a <meta name="viewport"> tag with width or initial-scale
A `<meta name="viewport">` not only optimizes your app for mobile screen sizes, but also prevents a 300 millisecond delay to user input. Learn more.TBT
Document has a <title> element
The title gives screen reader users an overview of the page, and search engine users rely on it heavily to determine if a page is relevant to their search. Learn more.
Document has a meta description
Meta descriptions may be included in search results to concisely summarize page content. Learn more.
Page has successful HTTP status code
Pages with unsuccessful HTTP status codes may not be indexed properly. Learn more.
Links have descriptive text
Descriptive link text helps search engines understand your content. Learn more.
Page isn’t blocked from indexing
Search engines are unable to include your pages in search results if they don't have permission to crawl them. Learn more.
Image elements have [alt] attributes
Informative elements should aim for short, descriptive alternate text. Decorative elements can be ignored with an empty alt attribute. Learn more.
Document uses legible font sizes 99.86% legible text
Font sizes less than 12px are too small to be legible and require mobile visitors to “pinch to zoom” in order to read. Strive to have >60% of page text ≥12px. Learn more.
Source
Selector
% of Page Text
Font Size
User Agent Stylesheet
input, textarea, select, button
0.14%
11px
Legible text
99.86%
≥ 12px
 
 
  
   Document avoids plugins   
     
 
  
Search engines can't index plugin content, and many devices restrict plugins or don't support them. Learn more.
 
 
 
  
 
 Not applicable (2)   
      
  
 
  
   robots.txt is valid   
     
 
  
If your robots.txt file is malformed, crawlers may not be able to understand how you want your website to be crawled or indexed. Learn more.
 
 
 
 
  
   Document has a valid rel=canonical   
     
 
  
Canonical links suggest which URL to show in search results. Learn more.
 
 
 
 
                                  
Progressive Web App
 
 
These checks validate the aspects of a Progressive Web App. Learn more.
 
Installable
 
  
   Web app manifest or service worker do not meet the installability requirements 1 reason  
     
 
  
Service worker is the technology that enables your app to use many Progressive Web App features, such as offline, add to homescreen, and push notifications. With proper service worker and manifest implementations, browsers can proactively prompt users to add your app to their homescreen, which can lead to higher engagement. Learn more.
 
 
Failure reason
No manifest was fetched
 
PWA Optimized
 
  
   Does not register a service worker that controls page and start_url   
     
 
  
The service worker is the technology that enables your app to use many Progressive Web App features, such as offline, add to homescreen, and push notifications. Learn more.
 
 
 
 
  
   Redirects HTTP traffic to HTTPS   
     
 
  
If you've already set up HTTPS, make sure that you redirect all HTTP traffic to HTTPS in order to enable secure web features for all your users. Learn more.
 
 
 
 
  
   Is not configured for a custom splash screen
Failures: No manifest was fetched.
   
     
 
  
A themed splash screen ensures a high-quality experience when users launch your app from their homescreens. Learn more.
 
 
 
 
  
   Does not set a theme color for the address bar.
Failures: No manifest was fetched,
No `<meta name="theme-color">` tag found.
   
     
 
  
The browser address bar can be themed to match your site. Learn more.
 
 
 
 
  
   Content is not sized correctly for the viewport
The viewport size of 656px does not match the window size of 360px.
   
     
 
  
If the width of your app's content doesn't match the width of the viewport, your app might not be optimized for mobile screens. Learn more.
 
 
 
 
  
   Has a <meta name="viewport"> tag with width or initial-scale   
     
 
  
A `<meta name="viewport">` not only optimizes your app for mobile screen sizes, but also prevents a 300 millisecond delay to user input. Learn more.TBT
 
 
 
 
  
   Does not provide a valid apple-touch-icon   
     
 
  
For ideal appearance on iOS when users add a progressive web app to the home screen, define an `apple-touch-icon`. It must point to a non-transparent 192px (or 180px) square PNG. Learn More.
 
 
 
 
  
   Manifest doesn't have a maskable icon
No manifest was fetched
   
     
 
  
A maskable icon ensures that the image fills the entire shape without being letterboxed when installing the app on a device. Learn more.
 
 
 
  
 
 Additional items to manually check (3)   These checks are required by the baseline PWA Checklist but are not automatically checked by Lighthouse. They do not affect your score but it's important that you verify them manually.
      
  
 
  
   Site works cross-browser   
     
 
  
To reach the most number of users, sites should work across every major browser. Learn more.
 
 
 
 
  
   Page transitions don't feel like they block on the network   
     
 
  
Transitions should feel snappy as you tap around, even on a slow network. This experience is key to a user's perception of performance. Learn more.
 
 
 
 
  
   Each page has a URL   
     
 
  
Ensure individual pages are deep linkable via URL and that URLs are unique for the purpose of shareability on social media. Learn more.