Supported subtitle and closed caption files

30/11/2019

A subtitle or closed caption file contains both the text of what is said in the video and time codes for when each line of text should be displayed. Some files also include position and style information, which is especially useful for deaf or hard of hearing viewers. See what file formats YouTube supports below.

Just getting started? Try adding captions directly in your video using our captions editor.

Basic file formats

If you’re new to creating caption files, we recommend using one of the following basic file types:

Format name	File extension	Additional information
SubRip	.srt	Only basic versions of these files are supported. No style information (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 information (markup) is recognized. The file must be in plain UTF-8.
MPsub (MPlayer subtitle)	.mpsub	"FORMAT=" parameter is supported.
LRC	.lrc	No style information (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 information, 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) example

1

      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 here

SubViewer (.sbv) example

0:00:00.599,0:00:04.160

      >> 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 here

Advanced file formats

Use these file formats if you want to have more control over styling (markup), positioning (where you want to have the captions show in the video), or both.

Format name	File extension	Additional information
SAMI (Synchronized Accessible Media Interchange)	.smi or .sami	Only timecodes, text, and simple markup (, , , and the *color= attribute within a ) are supported. Positioning is not supported.*
RealText	.rt	Only timecodes, text, and simple markup (, , , and the *color= attribute within a ) are supported. Positioning is not supported.*
WebVTT	.vtt	In initial implementation. Positioning is supported, but styling is limited to , , 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.

Broadcast file formats (TV and movies)

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	Additional information
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.

Scenarist Closed Caption (.scc file extension) files are our preferred file format. These files have an exact representation of CEA-608 data, which is the preferred format whenever captions are based on CEA-608 features.

* Nguồn: Youtube