What is a 304 Not Modified Response?
The 304 Not Modified HTTP response code indicates that the requested resource has not been modified since the last time it was accessed. This means the browser can display the cached version, and search engine crawlers know they don’t need to re-crawl the page.
How it Works:
- Initial Request: The server sends the resource with a 200 OK response and an ETag (hash code).
- Subsequent Request: The client sends a conditional request with If-None-Match (ETag) or If-Modified-Since (timestamp).
- Server Response: If the resource hasn’t changed, the server returns a 304 Not Modified response, and the cached version is used.
Why is the 304 Response Code Important?
For large websites, the 304 response saves crawl budget, allowing crawlers to focus on new and updated pages.
