Build a Cache-Control Header from Explicit Caching Intent

How to Use This Tool

Select directives, detect incompatible choices and copy one deterministic header. Build a Cache-Control response header from selectable directives and durations, with conflict checks for no-store, public, immutable and shared caches.

The work this page finishes

Developers often remember individual directives but combine mutually inconsistent storage, visibility and freshness intentions in one header. A visible row-by-row result preserves provenance, making a single correction possible without rerunning unrelated records or uploading the batch.

Deterministic workflow

Translate explicit checkbox intent into a stable directive order and fail the deployment state when public/private, no-store/storage, immutable/freshness or shared-cache prerequisites conflict. Input guards stop after 5,000 records or 2 MB, and the report separates fatal input problems from recoverable row warnings.

Why a dedicated interface helps

Copy only a conflict-free header, then test the real response and CDN behavior; the generated line represents policy intent, not proof of enforcement. Deterministic ordering, one-click copying and a downloadable artifact make repeated operational review easier than manually reconstructing a response from prose.

Assumptions

• Durations are nonnegative whole seconds after flooring.
• A shared-cache lifetime is emitted only with public selected.
• The user owns the response and understands invalidation strategy.

Do not discard the source after export: compare the destination result with it, and remember that local execution cannot secure the surrounding device or browser add-ons.

Limitations and review boundary

It does not model every extension directive, inspect a live response, choose a caching policy for the user or account for CDN-specific overrides. User values are never run as script, rendered as markup or fetched as network destinations; the page writes them only into text nodes.

Verification and provenance

On 2026-08-26, the rule and examples were cross-checked with RFC 9111 — HTTP Caching, including a known result, a rejected input and a conflict or duplicate case. The default produces public, max-age=31536000 and immutable with zero conflicts.