Cache-Control Builder: Browser & Shared Cache Policies

Build cache directives and compare browser and shared-cache policy scenarios while distinguishing validation, freshness and storage.

Enabling local controls…

1. Build a cache policy

Local processing; no website or cache lookups. Seconds: integers 0–2,147,483,647. Empty fields omit directives; whitespace, negatives, decimals, exponents and over-limit values are rejected. Input: 1 MiB UTF-8; header: 4 KiB.

Request / response

Cache storage visibility

max-age (optional seconds)

s-maxage (optional seconds)

stale-while-revalidate (optional seconds)

stale-if-error (optional seconds)

Directives no-cache no-store must-revalidate proxy-revalidate immutable no-transform

Scenario assumed current age in seconds (blank = 0; not added to header)

no-cache permits storage but requires successful validation before every reuse. no-store prohibits storage; private prohibits shared storage and does not guarantee privacy. must-revalidate requires successful validation after staleness, even offline. s-maxage overrides shared max-age and incorporates proxy-revalidate.

2. Header and offline scenario

Choose directives or a sample, then build.

Scenario uses only manually assumed current age. It does not read/calculate Age, Date, Expires, request time, response delay, Vary, Authorization, status, validators, CDN overrides or connectivity. This is not a full RFC cache simulator and cannot guarantee hits, storage or actual TTL.

How to use this tool

Choose directives and explicit lifetime values, review conflicts and the stated scenario assumptions, then copy the header and verify real server responses separately.

When not to use it

no-cache does not mean no storage, and private does not mean encrypted. This is not a cache implementation, CDN configuration check or proof of actual freshness or privacy.

Read the guide →