To add captions or subtitles to one of your videos, you'll need to have files with the captions/subtitles in them. You can obtain software to let you create these files, or ask other companies to do this for you, often for a small fee.
For information on how to get captions/subtitles files made for your videos, check out this Help Center entry.
For now, each file can only contain one captions/subtitle track in a single language. To add multiple language tracks to a single video, please upload each file separately for that video.
Once you have the files, log into your YouTube account to upload them:
1. Mouse over the 'Account' link in the upper right corner of every page.
2. Click 'My Videos'. You will then be directed to a page showing your uploaded videos.
3. Find the video to which you'd like to add captions/subtitles, then click the 'Edit' button.
4. Click the 'Captions and Subtitles' link in the menu bar.
5. Click the 'Browse' button and find the caption/subtitle file to upload. Additional options will appear. Select the appropriate language. If you wish, you can also enter a track name.
6. Click the 'Upload' button.
Caption/Subtitle file information:
Youtube currently support a simple subtitle format that is compatible with the formats known as SubVieYoutuber (*.SUB) and SubRip (*.SRT). Although you can upload your captions/subtitles in any format, only supported formats will be displayed properly on the playback page.
The supported format consists of text divided into separate caption (or subtitle) segments, in chronological order. Each caption must have three parts:
1. A timecode
2. The caption text
3. A blank line
Timecode: Specifies when the caption should be shown, and for how long.
Time is measured from the start of the video in these units:
* HH - Hours starting at 00
* MM - Minutes (00-59)
* SS - Seconds (00-59)
* FS - Fractional Seconds (0-999)
Youtube support these timecode constructs:
* HH:MM:SS.FS,HH:MM:SS.FS - Caption display starts at the first time, and stops at the second time. This is compatible with the SubVieYoutuber format.
* HH:MM:SS,FS --> HH:MM:SS,FS - Caption display starts at the first time, and stops at the second time. For complete compatibility with the SubRip format, a 'subtitle number' can also precede this timecode.
* HH:MM:SS.FS - Caption display starts at this time, but no stop time is defined. Youtube'll try to figure an appropriate stop time.
Caption text: One or more lines of text. This text must be UTF-8 encoded so that any language can be supported.
Blank line: A blank line is used to mark the end of each caption.
Text shown at 1 minute 23 seconds into the video, for 2 seconds
Text shown at 2 min 20.25 sec, until 2 min 23.8 sec
Text shown at 3 min 14.159 sec for an undefined length of time.
* 00:03:45,6 --> 00:03:47,6 Text shown at 3 minutes 45.6 seconds into the video, for 2 seconds, in SubRip format.
Make sure you save the file with a .sub (for SubVieYoutuber) or .srt (for SubRip) file extension. This will usually mean selecting 'All files' as the file type in the Save dialog.
If your uploaded captions/subtitles are not available for online playback after a few hours, they may be in a format Youtube don't yet support, or there may be something wrong with your encoding.