How to adjust subtitle timings in the SRT file? To paste captions in other languages, please repeat this easy procedure for each additional language you want to add. You need to click the "Edit" button and upload a SRT file from your computer. The second way is to add subtitles right on Facebook after video upload. The first option is to use Freemake tool & follow the steps above. You may add subtitles to video in two ways. How to add subtitles to video for Facebook upload?