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What does HTTP Status Code 304-Not Modified mean?
HTTP Status Code 304-Not Modified is one of the classes of 3xx(redirection) response code that indicates a conditional GET or HEAD request was received, which would have resulted in a 200 OK response if the condition had not been evaluated to false.
There is no need to retransmit the requested resources if the HTTP 304 Not Modified client redirection response code is returned. It’s a cached resource that’s being redirected implicitly. When the request method is safe, such as GET or HEAD, or when the request is conditional and contains an If-None-Match or If-Modified-Since header, this occurs.
Understanding HTTP Status Code 304 Requests
When you save a resource to your cache,then your browser saves the server’s ‘Last-Modified header’ information. When a browser receives a request for a web page it has saved but isn’t sure if it has the most recent version, it makes a “conditional validation” request to the server.
The ‘If-Modified-Since’ or ‘If-None-Match’ headers are used by the browser to convey the ‘Last-Modified’ date and time for the copy of the resource it possesses. The ETag value is likewise examined by the server when inspecting these headers. The latter is a one-of-a-kind identifier for a resource’s version.If the filenames are identical, the server provides the HTTP 304 Not Modified response header, and the browser utilizes the cached copy of the resource.
Common Causes of HTTP 304-Not Modified
Before we start solving this problem, it’s important to understand why it’s happening. There are a few typical reasons for HTTP 304 that you should be aware of.
One possibility is that your machine is infected with malware or a virus that is interfering with your browser’s caching functions. Another possibility is that damaged files in your browser are preventing it from correctly saving and updating data.
A problem with a third-party program or software is a third common cause. You may have installed a program or browser extension, for example, that is now interfering with your surfing experience.
Fixing the HTTP 304-Not Modified Status Code
| Clear you browser Cache |
| Disable your browser extensions for the time being. |
| Perform a Malware Scan |
| DNS and TCP/IP Settings Should Be Reset |
| Examine the configuration files on your server. |
Status
| 304 Not Modified |
Specification
Browser compatibility
304 Code References
| Rails HTTP Status Symbol | :not_modified |
| Go HTTP Status Constant | http.StatusNotModified |
| Symfony HTTP Status Constant | Response::HTTP_NOT_MODIFIED |
| Python2 HTTP Status Constant | httplib.NOT_MODIFIED |
| Python3+ HTTP Status Constant | http.client.NOT_MODIFIED |
| Python3.5+ HTTP Status Constant | http.HTTPStatus.NOT_MODIFIED |
Related Articles
| HTTP Status Code 205 Reset Content |
| HTTP Status Code 300-Multiple Choices |
| HTTP Status Code 302 Found |
| HTTP Status Code 204 – No Content |
| HTTP Status Code 207 Multi-Status |
FAQ
What does HTTP Status Code 304 mean?
308-Permanent Redirect status code is one of the classes of 3xx(redirection) response code that indicates a conditional GET or HEAD request was received, which would have resulted in a 200 OK response if the condition had not been evaluated to false.
There is no need to retransmit the requested resources if the HTTP 304 Not Modified client redirection response code is returned. It’s a cached resource that’s being redirected implicitly. When the request method is safe, such as GET or HEAD, or when the request is conditional and contains an If-None-Match or If-Modified-Since header, this occurs.
What are the causes of 304-Not Modified?
There are a few typical reasons for HTTP 304 that you should be aware of.
One possibility is that your machine is infected with malware or a virus that is interfering with your browser’s caching functions. Another possibility is that damaged files in your browser are preventing it from correctly saving and updating data.
A problem with a third-party program or software is a third common cause. You may have installed a program or browser extension, for example, that is now interfering with your surfing experience.
How can you fix 304-Not Modified?
Clear you browser Cache
Disable your browser extensions for the time being.
Perform a Malware Scan
DNS and TCP/IP Settings Should Be Reset
Examine the configuration files on your server.
Conclusion
I hope this article was able to help you with your doubts and queries related to the HTTP status code 304(Not Modified). Still, if there are any queries related to this topic, feel free to ask in the comment section, we would be happy to assist you. Thank you.
Saurabh Chalise