HTTP

HTTP 303 See Other vs 416 Range Not Satisfiable

HTTP 303 (See Other) is a 3xx Redirection response, while 416 (Range Not Satisfiable) is a 4xx Client Error response. 303 indicates that the server is redirecting to a different resource using GET, typically after a POST operation (Post/Redirect/Get pattern). In contrast, 416 means that the server cannot serve the requested byte range. The Range header value is outside the resource's size.

Description

The server is redirecting to a different resource using GET, typically after a POST operation (Post/Redirect/Get pattern).

When You See It

After form submissions to prevent resubmission on browser refresh.

How to Fix

Follow the Location header with a GET request. This is intentional — part of the PRG pattern.

Description

The server cannot serve the requested byte range. The Range header value is outside the resource's size.

When You See It

When requesting a byte range beyond the file's actual size.

How to Fix

Check the Content-Range in the response for the actual file size and adjust your Range header.

Key Differences

1.

303 is a 3xx Redirection response, while 416 is a 4xx Client Error response.

2.

HTTP 303: The server is redirecting to a different resource using GET, typically after a POST operation (Post/Redirect/Get pattern).

3.

HTTP 416: The server cannot serve the requested byte range. The Range header value is outside the resource's size.

4.

You encounter 303 when after form submissions to prevent resubmission on browser refresh.

5.

You encounter 416 when when requesting a byte range beyond the file's actual size.

When to Use Which

For 303 (See Other): Follow the Location header with a GET request. This is intentional — part of the PRG pattern. For 416 (Range Not Satisfiable): Check the Content-Range in the response for the actual file size and adjust your Range header.

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