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I'm looking for an official YouTube page that lists all of the audio formats and codecs used for YouTube videos. I can only find information posted by unofficial sources without citing their source for the information, such as this post.

YouTube will convert audio to ~24kbps(Mobile aka 3gp) ~64kbps(240p), ~128kbps(360p/480p) and ~192kbps(720p+) using the AAC and Opus (WebM only) codec.

However, I can't see any evidence to support this because I can't find any official YouTube page with the information despite searching.

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  • 1
    Do you mean playback resolution? I was looking this up a few weeks back when I was looking to get the best audio quality possible. I found an official page, but it just skimmed the surface. I did find out that if you have over 1000 views on a video, the audio quality increases from like 192kbps to 320. Also, the audio quality does not change with screen (playback) resolution.
    – n00dles
    Jun 22, 2016 at 12:08
  • Do you know where that page is? Jun 22, 2016 at 15:58
  • 1
    I commented rather than answered because I 'm not sure where the pages are. However, I just found this one where it states under 'bit ratre', "Audio playback bit rate is not related to video resolution.". But I can't find 1000 views info.
    – n00dles
    Jun 24, 2016 at 3:24
  • I had a look at that page before but it specifies the recommended bit rate for uploading rather than those available for downloading. My guess is that they once had the information on the site but later removed it for some reason. Jun 24, 2016 at 8:12

2 Answers 2

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Your best bet is to see what formats youtube-dl returns by running at a command-line,

youtube-dl -F URL

which will produce output looking like this

format code  extension  resolution note
249          webm       audio only DASH audio   53k , opus @ 50k (48000Hz), 4.25MiB
250          webm       audio only DASH audio   72k , opus @ 70k (48000Hz), 5.53MiB
140          m4a        audio only DASH audio  128k , m4a_dash container, mp4a.40.2@128k (44100Hz), 10.75MiB
251          webm       audio only DASH audio  139k , opus @160k (48000Hz), 10.81MiB
171          webm       audio only DASH audio  146k , vorbis@128k (44100Hz), 10.04MiB
160          mp4        256x144    DASH video  113k , avc1.4d400c, 25fps, video only, 9.28MiB
278          webm       256x144    DASH video  118k , webm container, vp9, 25fps, video only, 8.97MiB
133          mp4        426x240    DASH video  250k , avc1.4d4015, 25fps, video only, 20.77MiB
242          webm       426x240    DASH video  259k , vp9, 25fps, video only, 18.48MiB
243          webm       640x360    DASH video  472k , vp9, 25fps, video only, 33.50MiB
134          mp4        640x360    DASH video  633k , avc1.4d401e, 25fps, video only, 30.28MiB
244          webm       854x480    DASH video  829k , vp9, 25fps, video only, 56.73MiB
135          mp4        854x480    DASH video 1159k , avc1.4d401e, 25fps, video only, 58.66MiB
247          webm       1280x720   DASH video 1635k , vp9, 25fps, video only, 111.08MiB
136          mp4        1280x720   DASH video 2316k , avc1.4d401f, 25fps, video only, 108.68MiB
248          webm       1920x1080  DASH video 2930k , vp9, 25fps, video only, 206.66MiB
137          mp4        1920x1080  DASH video 4313k , avc1.640028, 25fps, video only, 194.91MiB
17           3gp        176x144    small , mp4v.20.3,  mp4a.40.2@ 24k
36           3gp        320x180    small , mp4v.20.3,  mp4a.40.2
5            flv        426x240    small , h263, mp3  @ 64k
43           webm       640x360    medium , vp8.0,  vorbis@128k
18           mp4        640x360    medium , avc1.42001E,  mp4a.40.2@ 96k
22           mp4        1280x720   hd720 , avc1.64001F,  mp4a.40.2@192k (best)

Looks like AAC, Opus, Vorbis, MP3 are all used. You can see the containers and most of the bitrates as well.

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  • It's not exactly what I was looking for but it is a clever alternative. Thanks. Jun 20, 2016 at 7:29
0

Though youtube-dl is a good source to learn about what formats you can stream in, it isn't the best source if you want to encode your media for YouTube. Ideally, you want to know what encoding options are used by Google or YouTube directly and this would also answer the question more accurately. A few links exist from Google and YouTube which can give you the appropriate insight you are asking for, I'll link the ones I found below.

Video and audio formatting specifications

Recommended upload encoding settings

Encoding specifications for music videos

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