How to Clear Browser Cache

What you are actually clearing

Modern browsers mix several stores: HTTP cache (disk/memory keyed by URL + validators), cookies and local/session storage, IndexedDB, service worker caches and scripts, prefetch hints, and sometimes DNS-over-HTTPS inside the browser. “Clear cache” UI options differ by vendor—narrow the scope so you do not wipe passwords or MFA state unnecessarily.

HTTP caching mechanics

Responses honor Cache-Control (max-age, no-store, private), ETag, and Last-Modified. A hard reload asks the browser to revalidate or bypass cache for that navigation, but service workers can still intercept fetch and serve their own cache. Use DevTools Disable cache (while DevTools is open) to reproduce what developers see on first load.

Goal	Typical approach	Tradeoff
Force fresh HTML/CSS/JS	Hard reload + DevTools disable cache	Still obeys no-store; SW may override
Fix stale SPA after deploy	Unregister SW / clear storage for origin	May log users out if cookies cleared
Rule out CDN	curl -I to origin vs edge with Host/SNI	Different from in-browser DoH path

HSTS and “stuck” HTTPS

If a site sent Strict-Transport-Security with a long max-age, the browser will refuse plain HTTP for that host—clearing cache does not remove HSTS pins quickly. That is separate from asset freshness.

After local clearing

If only one machine shows old assets, browser cache was likely. If every device does, purge CDN or fix origin Cache-Control. OS resolver cache is covered in Flush DNS cache.

Related: Clear Cloudflare cache, X-Forwarded-For explained (edge vs origin debugging), How DNS works.

Frequently Asked Questions

Q.Why does a hard refresh still show old JavaScript?

A service worker may be serving a cached bundle, or the HTML references fingerprinted filenames that did not change on deploy. Clear storage for the origin or unregister the worker, then reload.

Q.Does clearing cache log me out?

Only if you clear cookies or site data that hold the session. Many browsers offer cache-only clears—read the dialog carefully before confirming.

Q.What is the difference between cache and cookies?

HTTP cache stores fetched representations keyed by URL and validators. Cookies are small name/value strings sent on subsequent requests—clearing cache alone does not remove them.

Q.Will clearing the browser fix wrong DNS answers?

Not reliably—browsers may use DNS-over-HTTPS or the OS resolver. Use OS flush (ipconfig /flushdns, resolvectl flush-caches) or change resolver, then retest with dig/nslookup.

Q.Why does incognito still look cached?

Incognito avoids writing to the normal profile disk cache for some modes but still uses HTTP caching in memory for the session and may still use DoH—test with DevTools disable cache.

Q.Does clearing cache remove HSTS?

Generally no—HSTS is stored separately from ordinary HTTP cache entries and can persist until max-age expires or you use vendor-specific internal reset tools.

Q.How do I verify the browser is not the problem?

Compare curl -I from another network, or another browser profile with default settings, against the affected profile with extensions disabled.

Q.Should users clear cache for every support ticket?

No—use it after confirming timestamps, CDN age headers, and service worker status. Over-clearing trains users to skip better diagnostics.