about.readthedocs.com?ref=app.readthedocs.org speed test — 20 Oct 2026
Measured from the wfix.shop server on 20 October 2026 at 12:31 UTC. Grade A (96/100), with the screenshots, the timings and the fixes that matter.
Where the first byte went
- DNS lookup 81 ms 49%
- TCP connect 5 ms 3%
- Server wait 79 ms 48%
Measured on the connection that fetched the HTML. Every other request on the page waits for the end of this bar before it can start.
How this page compares
Every report published here is in this comparison, so it is a reference population of pages tested from one server - not a benchmark of the whole web.
What these numbers mean
- The server answered in 166 ms, which is fast: almost all of the wait is the page itself, not the host.
- The page transfers 367.7 KB over 22 request(s). Javascript files are 35% of it, so defer what is not needed for the first screen, and drop tags nobody uses.
- The HTML itself arrives gzip-compressed.
- It runs over HTTP/3, so the assets share a connection instead of opening one each.
- The largest element painted at 524 ms, inside the 2.5 s Google calls good.
- Layout stayed still (CLS 0.013), so nothing jumps under the reader's cursor.
- The main thread was blocked for 45 ms in total, which is not enough to feel.
Fix first: Render-blocking resources - Add defer or async to scripts that do not change the first paint, inline the critical CSS, and load the rest with media="print" plus an onload swap.
Read on one shared server, not a visitor's phone: use it to compare pages against each other, not as a promise about every connection. We fix what these tests find.
Screenshot
What the page looks like
Loaded in headless Chromium on this server. Click an image to open it full size.
Browser render
The same URL loaded in a real browser, so these are the readings curl cannot produce. The grade above is still built from the server measurements.
Page weight by type
What the page is made of
Transfer size, compressed as sent. 22 request(s) in total, 367.7 KB across all of them.
Top issues
Render-blocking resources
high impact4 render-blocking resource(s) in the document head (3 script(s), 1 stylesheet(s)). The page cannot paint until each one arrives.
Fix: Add defer or async to scripts that do not change the first paint, inline the critical CSS, and load the rest with media="print" plus an onload swap.
Avoid extra redirects
medium impact3 redirect hop(s) before the page load started, each one a full round trip before the first byte.
Fix: Link to the canonical URL (and make sure http, the apex domain and www all point at it) so no visitor pays a redirect first.
Strict-Transport-Security
low impactHSTS is not set, so the first visit on a hostile network can still be downgraded to HTTP.
Fix: Send Strict-Transport-Security with a max-age of at least six months. Add includeSubDomains once every subdomain is HTTPS.
Waterfall
Slowest requests
Each bar is one request's own response time, scaled to the slowest. Assets were fetched in parallel, so the bars overlap in real time rather than stacking. first party third party
| Request | Type | Status | Time | Size |
|---|---|---|---|---|
| https://about.readthedocs.com/?ref=app.readthedocs.org/images/homepage.png | html | 200 | 1.24 s | 6.2 KB |
| https://about.readthedocs.com/?ref=app.readthedocs.org/images/amd-logo.svg | html | 200 | 1.23 s | 6.2 KB |
| https://about.readthedocs.com/?ref=app.readthedocs.org/images/anaconda-logo.svg | html | 200 | 1.13 s | 6.2 KB |
| https://about.readthedocs.com/?ref=app.readthedocs.org/_/static/javascript/readthedocs-addons.js | html | 200 | 1.13 s | 6.2 KB |
| https://about.readthedocs.com/?ref=app.readthedocs.org/images/canonical-logo.svg | html | 200 | 1.09 s | 6.2 KB |
| https://about.readthedocs.com/theme/img/favicon-32x32.png | images | 200 | 1.05 s | 1.1 KB |
| https://about.readthedocs.com/theme/css/site.css | css | 200 | 1.04 s | 119.4 KB |
| https://about.readthedocs.com/theme/js/site.js | javascript | 200 | 1.04 s | 3.7 KB |
| https://about.readthedocs.com/theme/img/favicon.ico | images | 200 | 1.03 s | 3.5 KB |
| https://kit.fontawesome.com/53af4251af.js 3rd party | javascript | 403 | 1.03 s | 31 B |
| https://about.readthedocs.com/theme/img/favicon-24x24.png | images | 200 | 1.03 s | 918 B |
| https://about.readthedocs.com/?ref=app.readthedocs.org/images/jupyter-logo.png | html | 200 | 1.02 s | 6.2 KB |
| https://about.readthedocs.com/theme/js/vendor.js | javascript | 200 | 1.01 s | 126.8 KB |
| https://about.readthedocs.com/theme/img/favicon-16x16.png | images | 200 | 1.01 s | 704 B |
| https://github.com/mfisher87.png 3rd party | html | 302 | 1.00 s | 0 B |
| https://about.readthedocs.com/?ref=app.readthedocs.org/images/acquia-logo.svg | html | 200 | 999 ms | 6.2 KB |
| https://about.readthedocs.com/theme/img/apple-touch-icon.png | images | 200 | 991 ms | 9.9 KB |
| https://about.readthedocs.com/?ref=app.readthedocs.org/images/flask-logo.png | html | 200 | 991 ms | 6.2 KB |
| https://about.readthedocs.com/?ref=app.readthedocs.org/images/godot-logo.png | html | 200 | 986 ms | 6.2 KB |
| https://about.readthedocs.com/theme/img/logo-wordmark-dark.svg | images | 200 | 986 ms | 3.0 KB |
| https://avatars.githubusercontent.com/u/1654763?v=4 3rd party | images | 200 | 972 ms | 36.4 KB |
Report this page
Run this test on your own site
The same engine, free, with the screenshots and the fixes. No account needed.