HTTP

HTTP 304 Not Modified vs 414 URI Too Long

HTTP 304 (Not Modified) is a 3xx Redirection response, while 414 (URI Too Long) is a 4xx Client Error response. 304 indicates that the resource has not been modified since the last request. The client can use its cached copy. In contrast, 414 means that the URI provided was too long for the server to process.

Description

The resource has not been modified since the last request. The client can use its cached copy.

When You See It

When the browser cache is still valid (If-None-Match / If-Modified-Since headers match).

How to Fix

No fix needed. This saves bandwidth by confirming the cached version is still current.

Description

The URI provided was too long for the server to process.

When You See It

When query strings are extremely long or when accidentally sending a request body in the URL.

How to Fix

Shorten the URL. Move long parameters to the request body using POST instead of GET.

Key Differences

1.

304 is a 3xx Redirection response, while 414 is a 4xx Client Error response.

2.

HTTP 304: The resource has not been modified since the last request. The client can use its cached copy.

3.

HTTP 414: The URI provided was too long for the server to process.

4.

You encounter 304 when when the browser cache is still valid (If-None-Match / If-Modified-Since headers match).

5.

You encounter 414 when when query strings are extremely long or when accidentally sending a request body in the URL.

When to Use Which

For 304 (Not Modified): No fix needed. This saves bandwidth by confirming the cached version is still current. For 414 (URI Too Long): Shorten the URL. Move long parameters to the request body using POST instead of GET.

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