Pages requesting at least one missing (404) file, by platform (Sept 2026, top 1M, mobile)
| Platform | Any 404 | Missing script or stylesheet | Missing image | Pages |
|---|---|---|---|---|
| Shopify | 33.0% | 13.8% | 10.8% | 93,268 |
| Wix | 22.9% | 1.8% | 0.9% | 1,705 |
| Other or custom | 21.8% | 4.9% | 11.8% | 1,078,571 |
| WordPress | 19.3% | 5.2% | 9.2% | 222,205 |
| Webflow | 17.1% | 4.9% | 5.8% | 4,671 |
| Squarespace | 10.5% | 3.1% | 2.0% | 998 |
| All pages | 22.1% | 5.6% | 11.3% | 1,401,418 |
Source: PageSpeed Matters, Sept 2026. Includes third-party resources.
Summary
Every page asks the server for dozens of extra files: images, scripts, stylesheets and fonts. When one of those files has been moved or deleted, the server answers with a 404. The browser still makes the request and waits for the answer, and whatever that file was meant to do on the page simply does not happen.
We checked how common this is across the most visited sites on the web. Of 1,401,418 pages in HTTP Archive's top 1M crawl, 22.1% request at least one file that returns a 404, and 5.6% request a missing script or stylesheet, the kind of file that can change how the page looks or works.
What we measured
We looked at the HTTP Archive crawl from September 2026, on mobile, covering the top 1M sites by Chrome traffic. The sample includes both homepages and inner pages: 1,401,418 pages in all.
For each page we looked at every sub-resource request and its status code, and flagged pages where at least one request returned a 404. We also split those requests by type (image, script, stylesheet, font) and matched each page with its popularity tier, its platform and its Chrome UX Report (CrUX) field data.
Two limits matter. Third-party resources are included, so a 404 may come from an outside service, such as a widget or tracking script, rather than from the site itself. And the Core Web Vitals comparison below is a correlation, not proof that 404s slow pages down.
More than a fifth of pages request a missing file
310,159 of the 1,401,418 pages we checked, or 22.1%, request at least one file that does not exist. 78,042 pages (5.6%) request a missing script or stylesheet.
Images are the most common missing file. 11.3% of pages request an image that returns a 404, against 4.2% that request a missing script, 1.8% a missing stylesheet and 1.1% a missing font. A missing image usually leaves a gap or a broken icon. A missing script or stylesheet can be worse, because a feature or a style the page depends on never loads.
For most pages it is one or two files, but not all. 2.2% of pages (31,136) request five or more missing files, which can point to a theme, plugin or template that still references assets that were removed.
The problem is not limited to homepages. 22.6% of 782,850 homepages and 21.6% of 618,568 inner pages request a missing file, so the two are close.
22.1%
Share of 1,401,418 top 1M pages that request at least one file returning a 404.
Shopify pages hit the most 404s
Shopify pages are the most likely to request a missing file. 33.0% of 93,268 Shopify pages hit at least one 404, and 13.8% request a missing script or stylesheet. That compares with 19.3% and 5.2% of 222,205 WordPress pages, and 21.8% and 4.9% of 1,078,571 pages on other or custom platforms.
The data does not show where those Shopify 404s come from, and third-party files are included. One likely source is apps and embeds: stores often add and remove apps over time, and code that points at an app's files can stay behind after the app is gone.
Among the smaller platforms in the table, Squarespace pages are the cleanest at 10.5% of 998 pages, and Webflow sits at 17.1% of 4,671. Wix pages request a missing file at a similar rate to the overall average (22.9%), but only 1.8% request a missing script or stylesheet. These samples are small, so read them as rough indications.
The biggest sites are cleaner
The most visited sites are the least likely to request a missing file. 15.0% of 1,410 pages from Top 1K sites do, rising to 20.8% of 12,449 Top 10K pages, 21.9% of 120,761 Top 100K pages and 22.2% of 1,266,798 pages further down the top 1M.
The biggest sites are more likely to have teams and monitoring that catch broken references quickly. Below the Top 1K, though, the rate barely changes, so a missing file is about as likely on a mid-sized site as on a small one.
Pages with missing files pass Core Web Vitals less often
Pages that request a missing file pass Core Web Vitals less often. 42.9% of 189,829 such pages with CrUX data pass, against 47.9% of 690,525 pages without a 404.
This is a correlation, not proof that 404s slow pages down. A page that still requests deleted files may not have been maintained in a while, and the same neglect can show up in heavy images, old scripts and slow plugins. The missing files are best read as a sign of a page that needs attention, not as the cause of the gap.
What this means for your site
Missing files are one of the easiest problems to find and fix. Open a few key pages, such as the homepage, a product or service page and a blog post, with your browser's developer tools on the Network panel, reload, and filter by status code. Any request that returns a 404 is a file the page asks for and never gets.
For each one, decide whether the file should exist. If it should, restore it or update the path. If it should not, remove the reference from the theme, template or plugin that requests it. Pay most attention to scripts and stylesheets, since those can break features or layouts. On Shopify, check theme code for leftover app snippets after uninstalling an app.
Then make it routine. A monthly crawl with a site audit tool that reports broken resources will catch new 404s before they pile up.
Sources
- HTTP Archive crawl of the top 1M sites by Chrome traffic, September 2026, mobile: sub-resource requests and status codes
- Chrome UX Report (CrUX), September 2026: https://developer.chrome.com/docs/crux
- Web Vitals, web.dev: https://web.dev/articles/vitals
Embed this research
Paste this on your site to embed the chart. It links back to the source automatically.
<iframe id="psm-missing-file-statistics" src="https://www.pagespeedmatters.com/embed/data-studies/missing-file-statistics" width="100%" height="600" style="width:100%;border:1px solid #E2E3E1;border-radius:12px" loading="lazy" title="Missing File Statistics: 22.1% of Top 1M Pages Load a 404 - PageSpeed Matters"></iframe>
<script>window.addEventListener("message",function(e){if(e&&e.data&&e.data.psmEmbed==="missing-file-statistics"&&e.data.height){var f=document.getElementById("psm-missing-file-statistics");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/missing-file-statistics">Missing File Statistics: 22.1% of Top 1M Pages Load a 404 - PageSpeed Matters</a></p>
Frequently asked questions
How common are missing files (404s) on websites?
Common. 22.1% of 1,401,418 pages in HTTP Archive's top 1M crawl request at least one file that returns a 404, and 5.6% request a missing script or stylesheet.
What type of file is most often missing?
Images. 11.3% of pages request an image that returns a 404, against 4.2% for scripts, 1.8% for stylesheets and 1.1% for fonts.
Do 404 errors on page resources hurt Core Web Vitals?
Pages that request a missing file pass Core Web Vitals less often, 42.9% against 47.9% for pages without one. That is a correlation, not proof that the 404s cause the gap.
How do I find missing files on my site?
Open the page with your browser's developer tools on the Network panel, reload, and filter or sort by status code. Any request that returns a 404 is a missing file the page still asks for.
Missing files are quick to find and usually quick to fix, and clearing them out keeps scripts, styles and images working the way the page expects. Need help with this? See our website maintenance services.