Cache Header Checker

Description & Example

Caching reduces the number of requests a browser must make by storing resources locally. This tool examines the HTTP caching headers that instruct browsers on how to cache content.

The tool sends a HEAD request to the specified URL and extracts headers such as Cache-Control, Expires, Last-Modified, and ETag. Cache-Control specifies how long a resource may be cached, while Expires indicates a fixed date when the resource is no longer fresh. Last-Modified provides the timestamp of the resource’s most recent change, and ETag serves as a unique identifier for that specific version.

For example, a request to https://www.example.com might return:

These headers show that the resource is cached for up to one year and that its version is uniquely identified. Correct caching reduces load times by preventing redundant downloads.

The tool provides clear, objective data to assess your caching setup and improve site performance.