What is the HEAD method?
The HEAD method requests the headers that would be returned if the corresponding GET request was executed, but without transmitting the actual response body.
API Usage & Best Practices
- Check existence: Useful to check if a large resource (like a file or dataset) exists at a URL without downloading the file itself.
- Validate cache: Clients can send a HEAD request with conditional cache headers (
If-None-Match) to verify if their cached copy is still fresh. - Header consistency: The headers returned in a HEAD response must be identical to the headers that would have been returned by a GET request to the same URI.
Common Response Codes
- 200 OK: The resource exists.
- 304 Not Modified: The client’s cached version is identical.
- 404 Not Found: The resource does not exist.
