WWW/non-WWW and http handling by platform
| Platform | Swapped-host sites | Serve both hosts | Swapped host errors | http:// sites | 200 over plain http |
|---|---|---|---|---|---|
| Shopify | 1,788 | 0.2% | 0.6% | 1,888 | 0.4% |
| WordPress | 4,075 | 2.7% | 2.2% | 4,250 | 3.4% |
| Wix | 137 | 0.0% | 0.7% | 138 | 0.7% |
| Webflow | 40 | 10.0% | 0.0% | 46 | 4.3% |
| Other or custom | 5,031 | 10.6% | 2.4% | 5,975 | 4.5% |
| All | 11,071 | 5.9% | 2.0% | 12,394 | 3.5% |
Source: PageSpeed Matters, Oct 2026. Homepage requests only; swapped hosts with no connection are excluded. Wix and Webflow samples are small.
Summary
Every site should have one main address. If example.com is the main version, a request for www.example.com should redirect there, and the reverse. When both hosts serve the same page, search engines see two copies of every URL and have to pick one, and links and signals can end up split between them.
We tested this on sites that rank in Google. When we requested the opposite host on 11,071 ranking sites, most redirected correctly, but 5.9% served the page on both hosts. The platform a site runs on goes with the biggest difference.
What we measured
We drew the sites from the domains ranking in Google's top 20 for 10,019 US searches. For each site tested we took the main homepage, swapped the host (adding or removing www) and requested it. We also requested the http:// version of the homepage.
The host of the final URL decides the result. If the swapped request ends on the main host, the site redirected correctly. If it stays on the swapped host with a 200, the site serves both. Requests with no connection, which are likely DNS failures, are excluded from the www figures, leaving 11,071 sites where the swapped host resolved. The http test covers 12,394 homepage requests.
Platform comes from the main homepage request. Vertical and best rank come from the ranking data. The data was collected in October 2026 and covers homepage requests only, so inner pages may behave differently.
Most sites redirect to one main version
Of the 11,071 ranking sites where the swapped host resolved, 91.8% redirected to the main version and 0.3% redirected somewhere else. 5.9% served the page on both hosts, and 2.0% returned an error.
Which host is the main one matters. Sites whose main version is the bare domain handle the opposite host worse: 7.2% of 5,171 serve both and 3.0% error. Of the 5,900 sites that use www as the main host, 4.7% serve both and 1.1% error. A likely reason is that on a bare-domain setup the www host is an afterthought that someone has to configure, while sites that chose www often set up the bare domain redirect from the start.
The http to https move is in better shape. Of 12,394 http:// homepage requests, 95.6% ended on https. But 3.5% of sites still serve a 200 over plain http, which means the same page is reachable without encryption.
5.9%
Share of 11,071 ranking sites that served the homepage on both www and non-www instead of redirecting to one.
Platform makes the biggest difference
Duplicate hosts vary sharply by platform. 10.6% of 5,031 custom or other-platform sites serve the homepage on both www and non-www, against 2.7% of 4,075 WordPress sites and 0.2% of 1,788 Shopify stores.
The same pattern holds for plain http. It still loads without redirecting on 4.5% of 5,975 custom or other-platform homepages and 3.4% of 4,250 WordPress homepages, against 0.4% of 1,888 Shopify stores.
Hosted platforms usually handle host and protocol redirects at the platform level, so store owners rarely have to set them up. On custom stacks and self-hosted WordPress, the redirect lives in the server or CDN configuration, and it is easy to miss when a site moves hosts. The Wix and Webflow groups in the table are small, so their figures are a rough guide only.
Top-ranked sites are cleaner
Sites that hold top results are less likely to serve both hosts. 3.8% of 1,228 sites holding a #1 result serve both, against 5.4% for best ranks 2 to 5 and 6 to 10, and 7.2% of 4,035 sites whose best rank is 11 to 20. For plain http, the 200 rate is 2.2% for #1 sites against 4.0% for sites ranked 11 to 20.
This is a correlation. A duplicate host does not stop a site from ranking, and sites that rank #1 are likely better maintained in many ways at once.
By vertical, online stores and product sites are least likely to serve both hosts (3.9% of 4,251), while software and marketing sites are most likely (8.2% of 1,126). Platform mix likely explains part of this, since many stores run on hosted platforms that handle the redirect for them.
What this means for your site
The check takes a minute, and the fix is usually one redirect rule.
- Type your domain with and without www, and with http://, and note where each one ends up.
- Every version should end on one address with a single permanent 301 redirect, not a 200.
- Set the redirect at the server or CDN level so it covers every URL, not only the homepage.
- Make sure your canonical tags, sitemap and internal links all use the same host as the redirect target.
- If you recently moved hosts or CDNs, check again. That is when these rules most often get lost.
Sources
- PageSpeed Matters analysis of Google top 20 results for 10,019 US searches, October 2026
- Google Search Central, consolidate duplicate URLs: https://developers.google.com/search/docs/crawling-indexing/consolidate-duplicate-urls
Embed this research
Paste this on your site to embed the chart. It links back to the source automatically.
<iframe id="psm-www-vs-non-www-redirects" src="https://www.pagespeedmatters.com/embed/data-studies/www-vs-non-www-redirects" width="100%" height="600" style="width:100%;border:1px solid #E2E3E1;border-radius:12px" loading="lazy" title="WWW vs Non-WWW Redirects: 5.9% of Ranking Sites Serve Both - PageSpeed Matters"></iframe>
<script>window.addEventListener("message",function(e){if(e&&e.data&&e.data.psmEmbed==="www-vs-non-www-redirects"&&e.data.height){var f=document.getElementById("psm-www-vs-non-www-redirects");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/www-vs-non-www-redirects">WWW vs Non-WWW Redirects: 5.9% of Ranking Sites Serve Both - PageSpeed Matters</a></p>
Frequently asked questions
Should my site use www or non-www?
Either works, as long as you pick one and redirect the other to it. In our sample, 5.9% of 11,071 ranking sites served the page on both hosts, and bare-domain sites did so more often (7.2%) than www sites (4.7%).
How common is serving a site on both www and non-www?
5.9% of 11,071 ranking sites served the homepage on both hosts. 91.8% redirected to the main version and 2.0% returned an error on the swapped host.
How do I check my www redirect?
Type your domain with and without www, and with http://, and check that each one ends on the same https address through a redirect. 3.5% of ranking sites still serve a 200 over plain http.
A missing host redirect is usually a single server or CDN rule, and adding it gives every page one clear address. Need help with this? See our technical SEO services.