The HTTP 416 error occurs when a request for a partial range of data is sent to the server, but that requested range is not available. This problem typically happens when the browser or client attempts to download part of a file, but the requested part goes beyond the actual limits of the file on the server. The reason for this error may stem from a request for a range that is larger than the size of the file or that the server does not have the capability to provide that range.
One of the main reasons for receiving this error is the presence of a non-existent range in HTTP headers. For example, requesting a partial range from a file that is larger than the actual file size results in this error occurring. For this reason, if the file size is not accessible or has not been calculated, the specific range request should be avoided.
To prevent this error, you can check whether the file size on the server is available or not, and if you do, be mindful that the requested range is within that available size. Additionally, remember that some servers may be configured by default to restrict certain ranges.
Sometimes, you might need to consider server configurations and network conditions to disregard the restricted request or ensure the server has the capability for what you are requesting. This process not only helps avoid HTTP 416 errors but can also reduce the latency of small downloads.
Let's illustrate a simple example of a range request and examine it with code:
GET /file.mp4 HTTP/1.1
Host: example.com
Range: bytes=0-1023
Here, we have made a request for a specific portion of the file:GET /file.mp4 HTTP/1.1: sending an HTTP request to the server to retrieve the file named file.mp4.Host: example.com: indicating the domain or address of the destination server for this request.Range: bytes=0-1023: requesting a range of bytes from 0 to 1023 from the server, specifically the first 1024 bytes of the file.