Checks / Links, canonical and speed
Pages cannot be revalidated
None of the sampled pages sends an ETag or Last-Modified header, so a crawler cannot ask whether a page changed and get a short 304 answer. Google's crawling guide recommends it: without it every revisit downloads the whole page and fewer pages get recrawled.
no_validators · Links, canonical and speed · Notice
What triggers it
On a sample of 20 or more pages, at least 90% send neither an ETag nor a Last-Modified header.
What to change
Send ETag or Last-Modified on HTML pages and answer a matching If-None-Match or If-Modified-Since with 304 Not Modified. Most web servers and CDNs do this when it is switched on.
Example
Response headers to add on your server or CDN:
ETag: "33a64df5"
Last-Modified: Tue, 27 Oct 2026 08:00:00 GMTHow to confirm the fix
- Run curl -sI <url> | grep -i -E 'etag|last-modified': at least one is there, then repeat with -H 'If-None-Match: <etag>' and expect 304
- Run a new crawl
How common it is
In the audits of our own sites on 26 Oct 2026 (4 sites): finding judged right on citedby.eu, hexaciv.com.
Source: finding audit 2026-10-26 (English).
About this check
| Check ID | no_validators |
|---|---|
| Report section | Links, canonical and speed |
| Severity | Notice |
| How it is decided | Measured: read directly from the page or the server's response. |
| Added | Before 19 Oct 2026 (versions 1 and 2), or a site-wide check with no version date yet |
| Status | Measured in every report |
| Report gives the code | No, the fix is described in words |
Related checks
- The home address changes language with the visitor's browser
- Meta refresh redirect
- Indexable page missing from the sitemap
- Links to addresses that have moved
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