Cache

You might say

The new styles are deployed, but some people still see the old version. Find out which cache layer has not updated.

Keep reusable results so later requests do not always return to the originWhen new CSS is deployed but an old style remains visible, the browser, a shared cache, or a CDN may still be reusing an older copy. Caching reduces waiting and repeated transfer; diagnose the layer that served the old result, because clearing one browser does not prove a shared cache or origin has changed.

Know first

HTTP Browser Storage CDN

Why one URL sometimes does not reach the origin

BrowserGET /app.css

→

Cached copyNo copy

→

Origin200 app.css

Network evidence200 · transferred 18 kB

How caching changes the version you see

A hit reuses a stored copy: When a browser or shared cache finds a reusable response, it can return the resource without contacting the origin, reducing wait and transfer. A request result does not always come from the origin.

An old copy can be revalidated: When a copy is stale, a cache may ask the origin whether it changed. An unchanged resource can produce 304; a changed one returns new content. Diagnose updates with hit, revalidation, and invalidation evidence.

Quick checkChoose the best answer

Your cleared browser now shows the new CSS, but people elsewhere still see the old version. What should you check first?

Check shared-cache or CDN hits, response headers, and whether the old copy was invalidatedKeep clearing localStorage because every old page comes from browser-saved dataEdit the CSS source again without checking which resource version the request received

You can say this to an AI Agent

Find out whether this old CSS comes from the browser cache, a CDN/shared cache, or the origin. Check the resource URL, response headers, and requests from different locations. Then invalidate the old copy or update the resource address as appropriate, and verify both local and external requests. Do not treat Browser Storage as the cache diagnosis.

Learn next

1Browser Storage→2CDN→