What does the Cache-Control HTTP header do?

The Cache-Control header dictates how browsers and intermediary CDNs cache webpage resources (HTML, CSS, JS, images). It specifies directives like public, private, max-age, s-maxage, and no-store.

What is the difference between Gzip and Brotli compression?

Brotli (br) is a newer compression algorithm developed by Google that achieves 15-25% smaller file sizes compared to traditional Gzip for text-based web assets like HTML, CSS, and JavaScript.

How do caching headers impact Core Web Vitals?

Proper browser caching ensures returning visitors load assets instantly from local disk rather than making repeated round-trip network requests, dramatically lowering Largest Contentful Paint (LCP) and Time to First Byte (TTFB).

Cache-Control Auditor

Audit HTTP caching headers, max-age directives, and Brotli/Gzip compression

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About This Tool

What is Cache-Control & Compression Auditor?

Audit HTTP caching headers, evaluate max-age directives, detect Brotli and Gzip compression, and optimize page speed.

The Cache-Control Checker inspects your server caching configuration (Cache-Control, ETag, Last-Modified, Vary, Age) and detects compression algorithms (Brotli vs Gzip) to ensure repeat visitors load pages at maximum speed.

Quick Guide

How to Use

Enter the URL of your webpage or API endpoint.

Click "Check Caching".

Inspect your caching and compression score (Grade A-F).

Review max-age duration, ETag revalidation, and Brotli/Gzip status.

Advantages

Why Use This Tool?

Accelerate page speed and lower Time to First Byte (TTFB)

Verify Brotli and Gzip compression active status

Audit CDN edge cache headers (Cloudflare, Fastly, Varnish)

Prevent stale content delivery with ETag revalidation