A fresh look at browser caches
Why old files can linger, and how to check without clearing everything.
Why the browser keeps a copy
Images, stylesheets and other files often stay the same between visits. Keeping a local copy reduces downloads and can make a page load faster. The site sends instructions that help the browser decide when to reuse or recheck that copy.
A refresh does not always mean a full download
A browser can ask whether a stored file has changed. If the server confirms that it has not, the browser can keep the existing copy. A normal reload therefore does not necessarily download every file again.
This is usually helpful. After a site update, however, an older stylesheet or image may make the page look inconsistent until the cached copy is refreshed.
Try the smallest useful change first
- Reload the page once and check whether the problem remains.
- Try a private browsing window to compare a separate browsing session. This is a comparison, not proof of a particular cause.
- If only one site is affected, use the browser's controls for that site's stored data before clearing everything.
Other places a copy can live
Websites may also use shared caches between the server and the browser. A service worker can manage local resources as well. Clearing your own browser data will not necessarily change a copy held elsewhere.
If an old version remains visible across multiple devices, report the affected page and the approximate time you noticed it to the site operator.