Browser Cache Policy Builder
Build a Cache-Control header for a resource.
Runs in your browser. Nothing is uploaded — your input is processed on this device and discarded when you close the tab.
Browser Cache Policy Builder
How to use this tool
- Enter your values in the fields above.
- Press Generate to see the result.
- Use Load sample to try the worked example, Copy result to copy it, or Clear to start again.
Worked example
A CSS file with a max age of 31536000 seconds and Immutable ticked gives “public, max-age=31536000, immutable”: browsers may reuse it for a year without re-checking.
What this tool does not do / Limits
This builds a header string only. It does not apply the header to your server, and the right values depend on how often each file really changes.
Frequently asked questions
Should HTML pages get a long max age?
Usually not. Pages change often, so a short or zero max age avoids visitors seeing stale content.
What does Immutable mean?
It tells the browser the file at this address will never change, so it need not re-check it during the max age.
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