Does iPhone/iPad Safari require 'Accept-Ranges' header for video?

Question

I've been having problems serving videos from my dev server that play in mobile Safari. My dev server does not support the 'Accept-Ranges' header and after reading a few forums I've discovered that may be my problem. Here is an example forum posting saying just that.

Is this correct? Does mobile Safari require the Accept-Ranges header? Can anyone point me to any Apple documentation actually stating that?

Thanks.

Armyn

Answer 1

I found some Apple documentation that says that it does in fact need that for video.

HTTP servers hosting media files for iOS must support byte-range requests, which iOS uses to perform random access in media playback. (Byte-range support is also known as content-range or partial-range support.) Most, but not all, HTTP 1.1 servers already support byte-range requests.

If you are not sure whether your media server supports byte-range requests, you can open the Terminal application in OS X and use the curl command-line tool to download a short segment from a file on the server:

curl --range 0-99 http://example.com/test.mov -o /dev/null

If the tool reports that it downloaded 100 bytes, the media server correctly handled the byte-range request. If it downloads the entire file, you may need to update the media server.

Source: Apple Documentation

Armyn

Answer 2

The answer above is helpful, but does not actually answer the question that was asked.

According to the HTTP RFC, the Accept-Ranges header is optional even when byte-range requests are supported.

However, the documented curl check implies that the answer is no: iOS does not require the Accept-Ranges header for video, but does require byte-range support with partial content (206) responses.

Disclaimer: I haven't checked it on an actual device.

Softcover

I have checked it on several actual devices - if I disable byte-range support on my server, any Safari browser will refuse to play the video. – Mencius

I think that part has already been established, but the question is whether it requires Accept-Ranges headers (which are not required by the RFC in order for byte-range requests to work). – Softcover

I was trying to help you out with actual device tests, but OK. – Mencius

Thanks! If there's a way to test the second part (with byte ranges and with/without accept-ranges headers), then we'll have the definitive answer. – Softcover