YouTube
Fitur > Teknologi video > Kualitas dan codec

YouTube awalnya menawarkan video dengan satu tingkat kualitas, yaitu resolusi 320x240 piksel dengan codec Sorenson Spark (varian dari H.263), dengan audio MP3 mono. Pada bulan Juni 2007, YouTube menambahkan opsi menonton video berformat 3GP di telepon genggam. Bulan Maret 2008, mode kualitas tinggi ditambahkan hingga resolusi 480x360 piksel. Bulan November 2008, mode HD 720p ditambahkan. Saat peluncuran 720p, pemutar YouTube diganti rasio aspeknya dari 4:3 menjadi layar lebar 16:9. Dengan fitur baru ini, YouTube mulai mengalihkan format kompresi video bakunya ke H.264/MPEG-4 AVC. Pada bulan November 2009, mode HD 1080p ditambahkan. Bulan Juli 2010, YouTube mengumumkan bahwa mereka telah meluncurkan serangkaian video berformat 4K, sehingga batas resolusinya naik hingga 4096x3072 piksel. Akan tetapi, per 2012 batas ini diturunkan menjadi 2048 x 1536.
Video-video YouTube tersedia dalam beragam level kualitas. Nama kualitas standar (SQ), kualitas tinggi (HQ), dan definisi tinggi (HD) sudah diganti dengan angka-angka yang mewakili resolusi vertikal video. Aliran video bakunya menggunakan format H.264/MPEG-4 AVC dengan audio AAC stereo.
Non-DASH
| itag value | Kontainer baku | Resolusi video | Enkode video | Profil video | Bitrate video(Mbit/s)  | Enkode audio | Bitrate audio (kbit/s)  |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 5 | FLV | 240p | Sorenson H.263 | — | 0.25 | MP3 | 64 |
| 6 | FLV | 270p | Sorenson H.263 | — | 0.8 | MP3 | 64 |
| 13 | 3GP | — | MPEG-4 Visual | — | 0.5 | AAC | — |
| 17 | 3GP | 144p | MPEG-4 Visual | Simple | 0.05 | AAC | 24 |
| 18 | MP4 | 360p | H.264 | Baseline | 0.5 | AAC | 96 |
| 22 | MP4 | 720p | H.264 | High | 2-3 | AAC | 192 |
| 34 | FLV | 360p | H.264 | Main | 0.5 | AAC | 128 |
| 35 | FLV | 480p | H.264 | Main | 0.8-1 | AAC | 128 |
| 36 | 3GP | 240p | MPEG-4 Visual | Simple | 0.175 | AAC | 36 |
| 37 | MP4 | 1080p | H.264 | High | 3–5.9 | AAC | 192 |
| 38 | MP4 | 3072p | H.264 | High | 3.5-5 | AAC | 192 |
| 43 | WebM | 360p | VP8 | — | 0.5 | Vorbis | 128 |
| 44 | WebM | 480p | VP8 | — | 1 | Vorbis | 128 |
| 45 | WebM | 720p | VP8 | — | 2 | Vorbis | 192 |
| 46 | WebM | 1080p | VP8 | — | — | Vorbis | 192 |
| 82 | MP4 | 360p | H.264 | 3D | 0.5 | AAC | 96 |
| 83 | MP4 | 240p | H.264 | 3D | 0.5 | AAC | 96 |
| 84 | MP4 | 720p | H.264 | 3D | 2-3 | AAC | 192 |
| 85 | MP4 | 1080p | H.264 | 3D | 3-4 | AAC | 192 |
| 100 | WebM | 360p | VP8 | 3D | — | Vorbis | 128 |
| 101 | WebM | 360p | VP8 | 3D | — | Vorbis | 192 |
| 102 | WebM | 720p | VP8 | 3D | — | Vorbis | 192 |
DASH (hanya video)
| itag value | Kontainer | Resolusi video | Enkode video | Profil video | Bitrate video (Mbit/s)  |
| --- | --- | --- | --- | --- | --- |
| 133 | MP4 | 240p | H.264 | Main | 0.2-0.3 |
| 134 | MP4 | 360p | H.264 | Main | 0.3-0.4 |
| 135 | MP4 | 480p | H.264 | Main | 0.5-1 |
| 136 | MP4 | 720p | H.264 | Main | 1-1.5 |
| 137 | MP4 | 1080p | H.264 | High | 2-3 |
| 160 | MP4 | 144p | H.264 | Main | 0.1 |
| 264 | MP4 | 1440p | H.264 | High | 4-5 |
DASH (hanya audio)
| itag value | Kontainer baku | Enkode audio | Bitrate audio (kbit/s)  |
| --- | --- | --- | --- |
| 139 | MP4 | AAC | 48 |
| 140 | MP4 | AAC | 128 |
| 141 | MP4 | AAC | 256 |
| 171 | WebM | Vorbis | 128 |
| 172 | WebM | Vorbis | 192 |
Live streaming
| itag value | Kontainer baku | Resolusi video | Enkode video | Profil video | Bitrate video (Mbit/s)  | Enkode audio | Bitrate sudio (kbit/s)  |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 92 | TS | 240p | H.264 | Main | 0.15-0.3 | AAC | 48 |
| 93 | TS | 360p | H.264 | Main | 0.5-1 | AAC | 128 |
| 94 | TS | 480p | H.264 | Main | 0.8-1.25 | AAC | 128 |
| 95 | TS | 720p | H.264 | Main | 1.5-3 | AAC | 256 |
| 96 | TS | 1080p | H.264 | High | 2.5-6 | AAC | 256 |
| 120 | FLV | 720p | H.264 | Main@L3.1 | 2 | AAC | 128 |
| 127 | TS | — | — | — | — | AAC | 96 |
| 128 | TS | — | — | — | — | AAC | 96 |
| 132 | TS | 240p | H.264 | Baseline | 0.15-0.2 | AAC | 48 |
| 151 | TS | 72p | H.264 | Baseline | 0.05 | AAC | 24 |
Keterangan:
| 0 | 1 | 2 | 3 |
| --- | --- | --- | --- |
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^[1]
itag is an undocumented parameter used internally by YouTube to
differentiate between quality profiles. Until December 2010, there was also a
URL parameter known as fmt that allowed a user to force a profile using
itag codes.
^[2]
Approximate values based on statistical data; actual bitrate can be higher or
lower due to variable encoding rate.
^[3]
Has metadata referring to "Elemental Technologies Live".
^[4]
Used as alternate audio tracks.
^1 itag is an undocumented parameter used internally by YouTube to differentiate between quality profiles. Until December 2010, there was also a URL parameter known as fmt that allowed a user to force a profile using itag codes.

^2 Approximate values based on statistical data; actual bitrate can be higher or lower due to variable encoding rate.

^3 itag 120 is for live streaming and has metadata referring to "Elemental Technologies Live".