Main document protocol by platform (top 1M homepages, Sept 2026)
| Platform | HTTP/3 | HTTP/2 | HTTP/1.1 | Advertise h3 | Homepages |
|---|---|---|---|---|---|
| Webflow | 55.9% | 39.3% | 4.8% | 70.8% | 2,500 |
| WordPress | 30.4% | 60.4% | 9.2% | 52.3% | 113,791 |
| Other/custom | 21.2% | 59.4% | 19.4% | 33.7% | 617,837 |
| Shopify | 4.0% | 95.9% | 0.1% | 97.7% | 47,012 |
| Wix | 3.3% | 96.7% | 0.0% | 98.4% | 892 |
| Squarespace | 3.3% | 96.1% | 0.6% | 4.1% | 513 |
| All | 21.6% | 61.7% | 16.7% | 40.4% | 782,570 |
Source: PageSpeed Matters, HTTP Archive, Sept 2026. One lab crawl from one location.
Summary
HTTP/3 runs over QUIC instead of TCP and is meant to cut connection setup time, especially on mobile networks. Most CDNs now support it, so we checked how many popular homepages actually load over it.
21.6% of top 1M homepages (168,654 of 782,570) load over HTTP/3. 61.7% load over HTTP/2 and 16.7% still use HTTP/1.1. Far more sites offer HTTP/3 than use it in a given visit: 40.4% advertise it.
What we measured
We looked at HTTP Archive's Sept 2026 mobile crawl of the top 1M sites by Chrome traffic. For each homepage we read the protocol and TLS fields of the main document request. A homepage advertises HTTP/3 when its Alt-Svc response header lists h3. Platform is identified from the same page.
This is one lab crawl from one location. A browser usually makes its first connection over HTTP/2 and only switches to HTTP/3 after it has learned the Alt-Svc hint, so the HTTP/3 share depends on whether the crawler had already seen that hint. Core Web Vitals figures use Chrome UX Report field data at the 75th percentile and are correlations.
About one in five homepages loads over HTTP/3
Of 782,570 top 1M homepages, 21.6% (168,654) load over HTTP/3, 61.7% (482,972) over HTTP/2 and 16.7% (130,774) still over HTTP/1.1. 40.4% (316,072) advertise HTTP/3 in their Alt-Svc header.
Encryption is in better shape. 86.3% of non-QUIC connections that report TLS 1.2 or 1.3 (440,222 of 509,857) negotiate TLS 1.3. HTTP/3 connections always use TLS 1.3, so they are not in that base.
The most popular sites are a little ahead. 25.9% of 7,498 Top 10K homepages and 25.5% of 67,281 Top 100K homepages load over HTTP/3, against 21.1% of 707,791 homepages in the rest of the top 1M.
21.6%
Share of 782,570 top 1M homepages whose main document loaded over HTTP/3 in the Sept 2026 crawl.
Advertising HTTP/3 is not the same as using it
Of the 316,072 homepages that advertise h3, 52.6% (166,238) loaded over HTTP/3 in this crawl, and 149,114 were fetched over HTTP/2.
That gap is expected from how HTTP/3 is discovered. The browser learns that a site supports HTTP/3 from a header on an earlier response, so a first visit often goes over HTTP/2 even when the server is ready for HTTP/3. Real visitors who come back probably connect over HTTP/3 more often than a single crawl suggests.
Platform defaults decide the protocol
Which protocol a homepage uses depends mostly on where it is hosted. 97.7% of 47,012 Shopify homepages advertise HTTP/3, but only 4.0% loaded over it in this crawl. Wix looks similar, with 98.4% advertising and 3.3% loading over it.
Webflow is the leader among platforms: 55.9% of 2,500 Webflow homepages loaded over HTTP/3. 30.4% of 113,791 WordPress homepages did, against 21.2% of other or custom sites.
HTTP/1.1 survives mainly on custom stacks. 19.4% of 617,837 other or custom homepages still load over it, against 9.2% of WordPress and under 0.1% of Shopify homepages. Sites on hosted platforms get a modern protocol by default, while self-managed servers keep whatever they were set up with.
Protocol alone does not predict field speed
Among homepages with CrUX data, those that loaded over HTTP/3 pass Core Web Vitals 39.1% of the time (139,112), against 43.5% over HTTP/2 (377,811) and 44.8% over HTTP/1.1 (83,315).
That does not mean HTTP/3 makes sites slower. The split reflects which sites use each protocol: the HTTP/3 group has a different mix of platforms and sites, and a single lab crawl only shows the protocol for one visit. Field speed usually depends more on what the page loads than on the transport underneath it.
What this means for your site
HTTP/3 is worth turning on, but it is a small part of overall speed. Treat it as part of keeping your hosting current.
- Check your homepage in the browser's network panel and add the Protocol column. Look for h3 on repeat loads, and check the response headers for Alt-Svc.
- If your host or CDN supports HTTP/3, enable it there. Most major CDNs offer it as a setting.
- If you are still on HTTP/1.1, move to at least HTTP/2. Self-managed servers often need a config change or a newer web server version.
- Make sure TLS 1.3 is enabled alongside TLS 1.2.
Sources
- HTTP Archive crawl of the top 1M sites by Chrome traffic, September 2026, mobile
- Chrome UX Report (CrUX) field data, September 2026
- MDN Web Docs, Alt-Svc header: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Alt-Svc
Embed this research
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<iframe id="psm-http-3-adoption" src="https://www.pagespeedmatters.com/embed/data-studies/http-3-adoption" width="100%" height="600" style="width:100%;border:1px solid #E2E3E1;border-radius:12px" loading="lazy" title="HTTP/3 Adoption 2026: 21.6% of Top 1M Sites - PageSpeed Matters"></iframe>
<script>window.addEventListener("message",function(e){if(e&&e.data&&e.data.psmEmbed==="http-3-adoption"&&e.data.height){var f=document.getElementById("psm-http-3-adoption");if(f){f.style.height=e.data.height+"px";}}});</script>
<p style="font:14px/1.5 system-ui,sans-serif">Source: <a href="https://www.pagespeedmatters.com/resources/data-studies/http-3-adoption">HTTP/3 Adoption 2026: 21.6% of Top 1M Sites - PageSpeed Matters</a></p>
Frequently asked questions
What percentage of websites use HTTP/3?
21.6% of top 1M homepages (168,654 of 782,570) loaded over HTTP/3 in HTTP Archive's Sept 2026 crawl. 40.4% advertise HTTP/3, 61.7% loaded over HTTP/2 and 16.7% still used HTTP/1.1.
Why does my site advertise HTTP/3 but load over HTTP/2?
Browsers learn about HTTP/3 from the Alt-Svc header on an earlier response, so a first visit often uses HTTP/2. Of 316,072 homepages that advertise h3, 52.6% loaded over HTTP/3 in our crawl and 149,114 were fetched over HTTP/2.
Does HTTP/3 make a website faster?
Our data does not show a protocol effect. Homepages that loaded over HTTP/3 pass Core Web Vitals 39.1% of the time, against 43.5% over HTTP/2 and 44.8% over HTTP/1.1, which reflects which sites use each protocol rather than the protocol itself.
How do I check if my site uses HTTP/3?
Open the browser's network panel, add the Protocol column and reload the page. A value of h3 means HTTP/3, and an Alt-Svc response header listing h3 means the server advertises it.
Moving to HTTP/2 or HTTP/3 and TLS 1.3 is usually a hosting or CDN setting, and it keeps the foundation of your site current. Need help with this? See our website maintenance services.