What does clearing your browser cache actually do?
The cache stores copies of files a site has already sent you, such as images, stylesheets and scripts, so a return visit loads from your disk instead of the network. Clearing it deletes those copies, and the next visit to each site downloads everything again.
This is why clearing the cache fixes a specific class of problem: a site that looks broken, shows outdated content, or behaves oddly after an update. The site changed, your browser kept using the old files, and the mismatch produced the fault. Clearing forces a fresh copy and resolves it.
It is worth distinguishing cache from the other things usually offered alongside it, because they have quite different consequences.
- Cookies store your login sessions and site preferences. Clearing them logs you out of everything and resets settings such as language or consent choices. This is the one people regret, and it is frequently selected accidentally because it sits next to the cache option.
- Site data covers storage that web applications use for offline content and local state. Clearing it can remove drafts or downloaded data in applications that rely on it.
- History is only your record of visited pages and has no effect on how sites behave.
Clearing the cache does not speed up your computer in general, does not free meaningful disk space on a modern machine, and does not improve privacy much on its own since cookies are the tracking mechanism.
For diagnosing one misbehaving site, a hard reload that bypasses the cache for that page is a better first step than clearing everything, since it keeps you logged into every other site while achieving the same effect where it matters.