Conditional GET (304) Support

search What we check

Whether your server answers 304 Not Modified when a crawler re-requests the page with the validators it was given (If-Modified-Since / If-None-Match).

build How to fix

1. 1 Make sure the server honours If-Modified-Since and If-None-Match for content pages.
2. 2 Most frameworks expose this (for example fresh_when in Rails); enable it on article and content controllers.
3. 3 Keep the ETag and Last-Modified stable while the content is unchanged: an ETag computed from a body with a per-request CSRF or session token changes on every request, so a 304 can never happen.
4. 4 Behind a CDN that strips ETag, conditional GET still works through Last-Modified alone - that is fine.

menu_book Sources

• MDN: HTTP Conditional Requests open_in_new
• Bing Webmaster Guidelines open_in_new

link Related checks