Parse Cache-Control directives and inspect TTL and conflicts
Quick CTA
Paste one Cache-Control header per line and inspect TTL, public/private visibility, and warnings first; conflict cases and fixes stay in Deep.
Deep expands pitfalls, recipes, snippets, FAQ, and related tools when you need troubleshooting or deeper follow-through.
Cache-Control Parser decodes HTTP Cache-Control headers into structured directives so you can reason about browser and CDN behavior faster. Paste one or multiple lines and instantly see normalized directives, cacheability, visibility (public/private), TTL signals (max-age or s-maxage), and warning hints for contradictory combinations. This is useful for API responses, static asset caching, and reverse-proxy tuning where a tiny header mistake can cause stale content or cache misses. The parser also helps teams review policy changes before release and keep cache behavior predictable across environments. All processing is local in your browser.
no-store
Use it for highly sensitive or strictly non-persistent responses.
no-cache
Use it when caches may store the response but must revalidate before serving it again.
Note: Many teams say “disable cache” when they actually mean revalidate on every reuse, which is no-cache rather than no-store.
Presence checks
Use for quick header linting.
Behavior modeling
Use for CDN/browser consistency debugging.
Note: Real cache behavior depends on directive combinations, not single tokens.
One-size policy
Use for tiny sites with uniform content volatility.
Route classes
Use for apps mixing APIs, static assets, and personalized pages.
Note: Route-specific policies improve performance without harming freshness.
Fast pass
Use for low-impact exploration and quick local checks.
Controlled workflow
Use for production delivery, audit trails, or cross-team handoff.
Note: Cache Control Parser is more reliable when acceptance criteria are explicit before release.
Direct execution
Use for disposable experiments and temporary diagnostics.
Stage + verify
Use when outputs will be reused by downstream systems.
Note: Staged validation reduces silent compatibility regressions.
Bad input: Conflicting directives emitted by layered middleware.
Failure: Different intermediaries choose inconsistent caching behavior.
Fix: Normalize final header emission and remove contradictory directives.
Bad input: Missing `private`/`no-store` on personalized endpoints.
Failure: Potential data leakage through shared caches.
Fix: Enforce strict private caching rules on user-specific responses.
Bad input: Boundary values are not covered by acceptance fixtures.
Failure: Output appears valid locally but fails during downstream consumption.
Fix: Normalize contracts and enforce preflight checks before export.
Bad input: Security-sensitive values leak into debug traces.
Failure: Same source data yields inconsistent outcomes across environments.
Fix: Declare compatibility constraints and verify with an independent consumer.
Q01
no-store means do not keep the response at all; no-cache allows storage but requires revalidation before reuse.
Q02
Shared caches such as CDNs prioritize s-maxage, while browsers typically follow max-age and private/public semantics.
Recommend: Use long `max-age` plus immutable directives.
Avoid: Avoid short TTLs that defeat cache efficiency.
Recommend: Use private/no-store policies with explicit revalidation strategy.
Avoid: Avoid shared-cache-friendly directives.
Recommend: Use fast pass with lightweight verification.
Avoid: Avoid promoting exploratory output directly to production artifacts.
Recommend: Use staged workflow with explicit validation records.
Avoid: Avoid one-step execution without replayable evidence.
Cause: The directives send contradictory signals, so teams and intermediaries may interpret the policy differently.
Fix: Choose one intent clearly: either fully disable storage or define an explicit cache lifetime.
Cause: Responses that depend on cookies or user identity can leak through shared caches when marked public.
Fix: Use private or disable storage for personalized content, then verify cookie interactions separately.
Goal: Confirm whether your current Cache-Control policy is safe for both browsers and shared caches.
Result: You can tell whether the response should be cached, revalidated, or bypassed before production changes.
Goal: Validate assumptions before output enters shared workflows.
Result: Delivery quality improves with less rollback and rework.
Goal: Convert recurring failures into repeatable diagnostics.
Result: Recovery time drops and operational variance shrinks.
HTTP
Cache-Control: public, s-maxage=300, stale-while-revalidate=30Cache-Control Parser is most reliable with real inputs and scenario-driven decisions, especially around "Static fingerprinted assets".
It shows normalized directives, cacheability status, visibility, TTL hints, and warnings for conflicting directives.
Yes. It flags common conflicts such as no-store with max-age or public with private.
TTL is inferred from s-maxage first, then max-age when numeric values are present.
CDNs often prioritize shared-cache directives like s-maxage, while browsers use max-age and private/public semantics differently.
Yes. You can paste one Cache-Control value per line and review each line independently.
Yes. Your header values are analyzed locally in your browser.