Adding Captions to Videos 

Adding Captions to YouTube Videos

1. Use the YouTube Caption Editor.  YouTube automatically generates captions for most videos when they’re uploaded using speech recognition technology. These machine-generated captions are rarely if ever fully accurate. However, if their accuracy is decent and captions can be perfected with only a few minor corrections, the easiest way to correct them is to do so directly in YouTube.  For instructions see the  Edit Captions help page on YouTube.
2. Outsource. Companies such as Automatic Sync Technologies,  3PlayMedia, cielo24, and many other captioning service providers will caption videos for a fee.  Contact these companies directly for additional information.
3. Do it yourself.  There are free tools available online that make it possible and easy to caption your own video. See Captioning your own video for free for additional information.

The end product generated by the second and third options is a caption file. Most caption files are plain text files with time codes indicating the start and stop times. Popular caption file formats include SRT, WebVTT, and TTML, all of which are supported by YouTube.

To add captions to videos on YouTube, you must be the owner of the YouTube account where the video is hosted. The specific steps for uploading your caption file change frequently as the YouTube interface is upgraded. However, the general sequence is fairly consistent.

Step 1. Login to YouTube, then go to Video Manager

Currently Video Manager is located within the Upload menu, accessed by clicking Upload.

Note: Depending on your YouTube configuration your videos might not be displayed under Video Manager and instead listed under Creator Studio. 

Step 2. Find the video you want to add captions to, select Captions

Video Manager features a list of all your current videos. Currently each video includes an Editbutton. Click on the Edit button to reveal the Captions option.

Step 3. Upload your caption file

The Captions area within Video Manager includes a variety of features for managing your video’s captions and subtitles. One of the options is Upload a File. Select that option, then follow the prompts to upload your caption or subtitle file and identify the language. After you upload your file the new captions or subtitles will be live on YouTube within seconds.

YouTube also includes its own caption editor as well as a variety of other features related to captions and subtitles. For additional information see YouTube’s Help page on Captions.

Adding Captions to Videos on Web Pages

HTML5 introduced two new elements, <audio> and  <video>, which make it easy to add media files to web pages, and in some browsers (especially Internet Explorer) the default media player is highly accessible for keyboard users and screen reader users.

When adding video to a web page, it is important to add captions. In HTML5 this is done with the <track> element. In the following example, a video file named myvideo is provided in both MP4 and WebM formats to ensure cross-browser compatibility. English captions are provided in Web Video Text Tracks (WebVTT) format using the <track> element.

    <video preload="auto" width="480" height="360" poster="myvideo.jpg"> <source type="video/mp4" src="myvideo.mp4"/> <source type="video/webm" src="myvideo.webm"/> <track kind="captions" src="myvideo.vtt"/> </video>
    

HTML5 also includes a powerful API that enables developers to create their own media players. One such player called Able Player includes a wide variety of features and was specifically designed with accessibility in mind. It was originally developed at The University of Washington and is now maintained as an open source project on GitHub. Able Player is the player used on the DO-IT Video site.