Paste one response policy
Enter the Cache-Control value alone, a Cache-Control header line or one complete response header block. Multiple Cache-Control fields in that block are combined.
Cache-Control Checker
Explain pasted response Cache-Control directives, flag conflicting values and distinguish browser from shared-cache freshness lifetimes.
Free
No sign-up
Runs in your browser
Result
Your result will appear here
Declared lifetimes are not remaining freshness. Age, Expires, request rules and actual CDN behavior are not calculated.
What is Cache-Control Checker?
Cache-Control Checker is a free online website tool from GigaTools. Explain pasted response Cache-Control directives, flag conflicting values and distinguish browser from shared-cache freshness lifetimes. It runs entirely in your web browser, so nothing is uploaded and it works on any device without installing software.
Common uses
- Explain why no-cache differs from no-store.
- Review max-age and s-maxage for a proposed static asset policy.
How it works
How to use Cache-Control Checker
Separate storage from reuse
Read the notes for no-store, no-cache and private. Inspect numeric durations and any repeated, malformed or conflicting directives.
Verify actual cache behavior
Treat the displayed seconds as declared freshness lifetimes, not time remaining. Test your real response and CDN configuration before changing a production policy.
FAQ
Good to know
How do I use Cache-Control Checker?
1. Paste one response policy: Enter the Cache-Control value alone, a Cache-Control header line or one complete response header block. Multiple Cache-Control fields in that block are combined. 2. Separate storage from reuse: Read the notes for no-store, no-cache and private. Inspect numeric durations and any repeated, malformed or conflicting directives. 3. Verify actual cache behavior: Treat the displayed seconds as declared freshness lifetimes, not time remaining. Test your real response and CDN configuration before changing a production policy.
Does no-cache mean that nothing is stored?
No. Unqualified no-cache allows storage but requires successful validation before reuse. no-store instructs caches not to store the response. This tool reviews response directives only.
Is the lifetime the remaining cache time?
No. Remaining freshness also depends on response age and timing. This checker does not calculate Age, Date or Expires, request directives, authorization rules, Vary behavior, cache keys or CDN overrides. It cannot certify that a response is actually cached.
Which argument forms need manual review?
Durations must be non-negative safe whole numbers. Repeated directives suppress lifetime inference. Field-name forms such as private="Set-Cookie" and no-cache="ETag" are preserved but not evaluated; extension and request directives remain uninterpreted.
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