How can I find out whether a server supports the Range header?

Question

I have been trying to stream audio from a particular point by using the Range header values but I always get the song right from the beginning. I am doing this through a program so am not sure whether the problem lies in my code or on the server.

How can I find out whether the server supports the Range header param?

Thanks.

Answer 1

The way the HTTP spec defines it, if the server knows how to support the Range header, it will. That in turn, requires it to return a 206 Partial Content response code with a Content-Range header, when it returns content to you. Otherwise, it will simply ignore the Range header in your request, and return a 200 response code.

This might seem silly, but are you sure you're crafting a valid HTTP request header? All too commonly, I forget to specify HTTP/1.1 in the request, or forget to specify the Range specifier, such as "bytes".

Oh, and if all you want to do is check, then just send a HEAD request instead of a GET request. Same headers, same everything, just "HEAD" instead of "GET". If you receive a 206 response, you'll know Range is supported, and otherwise you'll get a 200 response.

Answer 2

This is for others searching how to do this. You can use curl:

curl -I http://exampleserver.com/example_video.mp4 

In the header you should see

Accept-Ranges: bytes 

You can go further and test retrieving a range

curl --header "Range: bytes=100-107" -I http://exampleserver.com/example_vide0.mp4 

and in the headers you should see

HTTP/1.1 206 Partial Content 

and

Content-Range: bytes 100-107/10000000 Content-Length: 8 

[instead of 10000000 you'll see the length of the file]