www.mozilla.org speed test — 20 Oct 2026
Measured from the wfix.shop server on 20 October 2026 at 12:33 UTC. Grade A (94/100), with the screenshots, the timings and the fixes that matter.
Where the first byte went
- DNS lookup 56 ms 21%
- TCP connect 20 ms 7%
- Server wait 192 ms 72%
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 first byte arrived in 268 ms. That is workable, and the cheapest win left is caching or a warmer connection.
- The page transfers 73.4 KB over 26 request(s). Javascript files are 52% of it, so defer what is not needed for the first screen, and drop tags nobody uses.
- The HTML itself arrives br-compressed.
- It runs over HTTP/3, so the assets share a connection instead of opening one each.
- The largest element painted at 520 ms, inside the 2.5 s Google calls good.
- Layout stayed still (CLS 0.091), so nothing jumps under the reader's cursor.
- The main thread was blocked for 284 ms, so taps and scrolling wait while scripts run.
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. 26 request(s) in total, 73.4 KB across all of them.
Top issues
Render-blocking resources
high impact8 render-blocking resource(s) in the document head (4 script(s), 4 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 impact1 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.
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://www.mozilla.org/media/js/sentry.b4fa63c42f81.js | javascript | 200 | 1.09 s | 20.1 KB |
| https://www.mozilla.org/media/img/logos/m24/wordmark-white.2d673bb5b33a.svg | images | 200 | 1.09 s | 500 B |
| https://www.mozilla.org/media/js/data.a3c1e6e4dfae.js | javascript | 200 | 1.08 s | 2.4 KB |
| https://www.mozilla.org/media/img/logos/0din/logo-0din.50589c5926d2.svg | images | 200 | 1.08 s | 297 B |
| https://www.mozilla.org/media/js/fxa.bf74c411a79c.js | javascript | 200 | 1.08 s | 2.2 KB |
| https://www.mozilla.org/media/img/logos/otari/otari-logo.24578ec1007a.svg | images | 200 | 1.07 s | 1011 B |
| https://www.mozilla.org/media/js/gtm-snippet.cc9550e6b401.js | javascript | 200 | 1.07 s | 833 B |
| https://www.mozilla.org/media/js/site.c6d6f1fa36a4.js | javascript | 200 | 1.07 s | 2.0 KB |
| https://www.mozilla.org/media/js/lib.57070d33021c.js | javascript | 200 | 1.06 s | 5.3 KB |
| https://www.mozilla.org/media/js/m24-ui.54a2e7c5dc9d.js | javascript | 200 | 1.06 s | 3.8 KB |
| https://www.mozilla.org/media/img/logos/tabstack/logo-tabstack.4551b75d8e6b.svg | images | 200 | 1.06 s | 158 B |
| https://www.mozilla.org/media/img/logos/thunderbird/logo-thunderbird.121e9c0fed45.svg | images | 200 | 1.06 s | 2.8 KB |
| https://www.mozilla.org/media/protocol/img/logos/firefox/browser/logo.eb1324e44442.svg | images | 200 | 1.06 s | 2.5 KB |
| https://www.mozilla.org/media/img/logos/mdn/mdn-plus-logo.c615b46ca4ce.svg | images | 200 | 1.06 s | 232 B |
| https://www.mozilla.org/media/protocol/img/logos/firefox/relay/logo.d42a8b52e44c.svg | images | 200 | 1.06 s | 1.5 KB |
| https://www.mozilla.org/media/protocol/img/logos/mozilla/vpn/logo.c648f487bfb8.svg | images | 200 | 1.05 s | 488 B |
| https://www.mozilla.org/media/protocol/img/logos/firefox/monitor/logo.d97e5516f9e6.svg | images | 200 | 1.05 s | 1.1 KB |
| https://www.mozilla.org/media/css/locales.67d2e1de4170.css | css | 200 | 1.04 s | 556 B |
| https://www.mozilla.org/media/css/m24-navigation-and-footer.038277dadfff.css | css | 200 | 1.04 s | 5.2 KB |
| https://www.mozilla.org/media/img/logos/m24/lockup-black.f2ddba3f0724.svg | images | 200 | 1.04 s | 613 B |
| https://www.mozilla.org/media/css/protocol-mozilla.eafbcba9bb2a.css | css | 200 | 1.04 s | 8.8 KB |
| https://www.mozilla.org/media/js/consent-banner.20ae7deac179.js | javascript | 200 | 1.04 s | 1.9 KB |
| https://www.mozilla.org/media/img/favicons/mozilla/favicon-196x196.e143075360ea.png | images | 200 | 1.04 s | 591 B |
| https://www.mozilla.org/media/img/favicons/mozilla/favicon.d0be64e474b1.ico | images | 200 | 1.04 s | 524 B |
| https://www.mozilla.org/media/img/favicons/mozilla/apple-touch-icon.05aa000f6748.png | images | 200 | 1.04 s | 467 B |
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