Cache-Control Analyzer
Paste a Cache-Control header value or full HTTP response headers to review directives, detect conflicts, and see a short policy summary. Analysis runs entirely in your browser; no server is contacted.
Analyze a pasted Cache-Control value or full HTTP response headers and review caching directives, numeric lifetimes, conflicts, and related cache validators without making a network request.
How to analyze Cache-Control
- Paste a Cache-Control value or a full response header block.
- Run the analyzer to inspect recognized directives, numeric values, policy summary, and parser issues.
- Review related headers such as ETag, Last-Modified, Expires, Age, and Vary when they are present.
What the analyzer checks
Recognized numeric directives include max-age, s-maxage, stale-while-revalidate, and stale-if-error; negative or malformed values are errors.
It flags conflicting duplicate values, public with private, and reviews combinations such as no-store with max-age or immutable. Unknown directives are displayed but not treated as recognized policy rules.
Privacy and limitations
The tool only parses the text you paste in your browser and never requests the target server. It does not measure real cache behavior, CDN configuration, browser cache state, intermediaries, or whether a response is actually cacheable in every deployment context.
Cache-Control Analyzer FAQ
Does it fetch my website?
No. Paste the header value or response headers manually.
Does it understand max-age?
Yes. Numeric cache lifetimes are parsed and validated.
Does it show ETag and related headers?
When full headers are pasted, supported related headers are summarized.
Will it detect every HTTP caching problem?
No. It checks the rules implemented by this analyzer, not live cache behavior.
Is any header data uploaded?
No. Analysis is browser-local.