A subtitle or closed caption file contains the text of what is said in the video. It also contains time codes for when each line of text should be displayed. Some files also include position and style info, which is especially useful for deaf or hard of hearing viewers. See what file formats YouTube supports below.
If you’re new to creating caption files, we recommend using one of the following basic file types:
| Format name | File extension | More info |
|---|---|---|
| SubRip | .srt | Only basic versions of these files are supported. No style info (markup) is recognized. The file must be in plain UTF-8. |
| SubViewer | .sbv or .sub | Only basic versions of these files are supported. No style info (markup) is recognized. The file must be in plain UTF-8. |
| MPsub (MPlayer subtitle) | .mpsub | "FORMAT=" parameter is supported. |
| LRC | .lrc | No style info (markup) is recognized, but enhanced format is supported. |
| Videotron Lambda | .cap | This file type is primarily used for Japanese subtitles. |
If you’re new to creating caption files, you may want to use SubRip (.srt) or SubViewer (.sbv). They only require basic timing info, and can be edited using any plain text editing software.
The main difference between SubRip and SubViewer files is the format of the caption start and stop times. Here are examples of both formats:
SubRip (.srt) example1
00:00:00,599 --> 00:00:04,160
>> ALICE: Hi, my name is Alice Miller and this is John Brown
2
00:00:04,160 --> 00:00:06,770
>> JOHN: and we're the owners of Miller Bakery.
3
00:00:06,770 --> 00:00:10,880
>> ALICE: Today we'll be teaching you how to make
our famous chocolate chip cookies!
4
00:00:10,880 --> 00:00:16,700
[intro music]
5
00:00:16,700 --> 00:00:21,480
Okay, so we have all the ingredients laid out here0:00:00.599,0:00:04.160
>> ALICE: Hi, my name is Alice Miller and this is John Brown
0:00:04.160,0:00:06.770
>> JOHN: and we're the owners of Miller Bakery.
0:00:06.770,0:00:10.880
>> ALICE: Today we'll be teaching you how to make
our famous chocolate chip cookies!
0:00:10.880,0:00:16.700
[intro music]
0:00:16.700,0:00:21.480
Okay, so we have all the ingredients laid out hereUse these file formats if you want to have more control over the styling (markup) or positioning of your captions.
| Format name | File extension | More info |
|---|---|---|
| SAMI (Synchronized Accessible Media Interchange) | .smi or .sami | Only timecodes, text, and simple markup (<b>, <i>, <u>, and the color= attribute within a <font>) are supported. Positioning is not supported. |
| RealText | .rt | Only timecodes, text, and simple markup (<b>, <i>, <u>, and the color= attribute within a <font>) are supported. Positioning is not supported. |
| WebVTT | .vtt | In initial implementation. Positioning is supported, but styling is limited to <b>, <i>, <u> since CSS class names are not yet standardized. |
| TTML (Timed-Text Markup Language) | .ttml | In partial implementation. SMPTE-TT extensions supported for CEA-608 features. iTunes Timed Text (iTT) file format is supported; iTT is a subset of TTML, Version 1.0. Styling and positioning are supported. |
| DFXP (Distribution Format Exchange Profile) | .ttml or .dfxp | These files types are interpreted as TTML files. |
These file formats are typically used for closed captions for broadcast content (TV and movies) and support either the CEA-608 or EBU-STL standards. YouTube tries to display the captions from these files as if they were on a TV — with the same styling, color, and positioning.
| Format name | File extension | More info |
|---|---|---|
| Scenarist Closed Caption | .scc | These files have an exact representation of CEA-608 data, which is the preferred format whenever captions are based on CEA-608 features. |
| EBU-STL (binary) | .stl | European Broadcasting Union standard. |
| Caption Center (binary) | .tds | Supports CEA-608 features. |
| Captions Inc. (binary) | .cin | Supports CEA-608 features. |
| Cheetah (ASCII text) | .asc | Supports CEA-608 features. |
| Cheetah (binary) | .cap | Supports CEA-608 features. |
| NCI (binary) | .cap | Supports CEA-608 features. |