Cache-Control Builder
Parse and build the Cache-Control header, while also generating normalized text, Nginx fragments, and conflict warnings.
Local browser processing
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User Guide
How to use the Cache-Control builder
The Cache-Control builder processes input only in the current browser; it does not upload, connect to the internet, or write to persistent storage.
Enter a directive
Use public, max-age, and stale-while-revalidate as default examples.
Check for conflicts
View duplicate directives, no-store/lifetime, and public/private warnings.
Copy configuration
Copy the Header or Nginx text, then review it separately for development and production environments.
Limitations and Notes
- Warning: this is not a general security guarantee; caching behavior also depends on the browser, CDN, proxies, and the application.
- Negative numbers, control characters, and invalid delta-seconds are rejected.
- The tool does not check the actual cache hit rate or make requests to the server or CDN.
FAQ
Can no-store and max-age be written together?
The tool allows parsing but flags conflicting or invalid combinations; whether to retain them is up to you.
Will it test CDN?
No; it only generates and checks local text.
Why does order matter?
To preserve user input and generate readable, reviewable Headers.