What is what does 304 mean?

The 304 Not Modified HTTP status code indicates that the resource requested by the client has not been modified since the last time the client accessed it. The server is essentially telling the client to use its cached version of the resource.

Here's a breakdown:

• Purpose: To reduce network bandwidth usage and server load by avoiding unnecessary data transfers.

• How it works: The client includes an If-Modified-Since or If-None-Match header in its request.

  • If-Modified-Since: Contains the date and time the client last received the resource.
  • If-None-Match: Contains an ETag (entity tag), which is a unique identifier for the resource version. If the resource on the server hasn't been modified since the date in If-Modified-Since or the ETag still matches, the server responds with a 304 Not Modified status.

• Response: The server's response body is empty (or minimally informative). The response headers may include headers regarding the cache, such as Cache-Control, Expires, ETag, or Vary.

• Client Action: The client uses its cached copy of the resource.

• Use cases:

  • Caching of static assets like images, CSS files, and JavaScript files.
  • Improving website performance by leveraging browser caching.

In summary, a 304 response signals successful conditional retrieval of a resource from the cache. Check out more about <a href="https://www.wikiwhat.page/kavramlar/HTTP%20Status%20Codes">HTTP Status Codes</a> and <a href="https://www.wikiwhat.page/kavramlar/Browser%20Caching">Browser Caching</a> for a more detailed explanation.