HTTP caching for https://cachecheck.net/examples/expires-and-max-age

Overview

✅

This resource can be cached.

This response can be cached because of a directive in the Cache-Control header.

✅

This resource has a cache control header.

Cache-Control: max-age=3600
❌

This resource does not have an entity tag.

HTTP response cache headers

These are the raw caching-related HTTP headers that were returned by the server:
cache-control: max-age=3600
expires: Mon, 15 Sep 2025 20:15:18 GMT
vary: Accept-Encoding
🧭

Cache-Control

Cache-Control: max-age=3600
  • ⏳
    Max Age
    (RFC)

    The max-age directive indicates the response should be considered stale after 3600 seconds (1 hour).

    For example, since this response was fetched on Sep 15, 2025, 7:15:18 PM, it will become stale on Sep 15, 2025, 8:15:18 PM.

🗑️

Expires

⚠️ The Expires header is redundant with the max-age directive in the Cache-Control header, so the Expires header will be ignored.

The Expires header indicates the time at which the response will expire.

Expires: Mon, 15 Sep 2025 20:15:18 GMT

In this case, the response will expire on Sep 15, 2025, 8:15:18 PM (in about 1 hour).

🔀

Vary

The Vary header indicates which request headers the server response may be dependent on. If any of the listed headers change, then the response may be different. This allows the server to send the correct cached response for each request. For example, ensuring that a client that does not support compression does not receive a cached compressed response.

Vary: Accept-Encoding

Accept-Encoding: The server response is expected to be different depending on the encodings that the client accepts via the Accept-Encoding header in the request. For example, if the client does not support compression, then the server may send a cached uncompressed response. If the client does support compression, for example, by sending a a Accept-Encoding: gzip header, then the server may send a cached compressed response.