The end product for captions is what is known as a sidecar file. There are various file types: .srt, .vtt, .scc, and more. These are versatile, text-based files that you then add to your video by uploading the caption file to the online platform where your video is hosted. Viewers can toggle these captions on or off.
For social media, you can think of this as a two-step process. First, you upload your video to a site such as Facebook, YouTube or Vimeo then you upload your caption file, .srt files being the most commonly used type of caption files.
Adding captions to YouTube
In your YouTube account, click on Your videos and then click on the video you wish to add captions to.
Click EDIT VIDEO button underneath the video.
Click the Subtitles link in the left menu and then select your language from the dropdown box if it appears (if you’ve already set your default language to English, you may not see this).
Click the blue Add link to open the subtitle creator.
Choose Upload a file and then select Subtitles file from the pop-up that appears. Choose your file and then click the blue Upload button.
Your captions will appear in the left pane next to the video. You can make adjustments there if you wish, and then click the blue Save changes button in the upper right.
That’s it! Your captions will now appear on your video. Be sure to click the CC button if you don’t see them while watching your video.
Here is an example of a Heliopolis produced video that has English and French captions:
Adding Captions to Vimeo
In the Vimeo Video Manager, click on the video that you are adding captions to.
In the left menu, click the Distribution tab arrow, then click Subtitles.
Click the “+” button, specify the Language, the Type (Captions), then click Choose File and upload the caption file.
Once the file is uploaded, you’ll need to toggle it on to activate it.
When you preview your video, you may need to click the CC button in the lower video pane menu and turn the captions on before they will appear.
Here is an example of an Heliopolis produced Vimeo video that has English and French captions: