How this tool works
Each caption is drawn onto the frames it belongs to and the video is encoded once, so the words become part of the picture. Load an SRT or VTT file, or write the lines yourself with a timestamp above each one. The preview shows a real frame with the caption on it, so the size and position can be judged before anything is encoded.
Burnt-in captions show everywhere: in a muted feed, in a player with no subtitle button, and after the video has been downloaded and reposted. A separate subtitle track is better where it is supported, because it can be turned off and translated — but most social platforms do not show one at all, which is why the words are put into the picture here. This does not listen to the video; the words come from you, because automatic transcription needs a speech model far too large to load in a browser.
Captions people can actually read
- Every line gets an outline, whatever else you choose: white text alone disappears the moment the footage behind it turns pale, and that is the usual reason burnt-in captions fail. The outline costs nothing and works over anything.
- Feeds play silently, so captions carry the message: most social video autoplays muted, which means a clip that depends on its audio to make sense already fails for most of the people who see it. Captions are not an accessibility extra there; they are the content.
- Size for a phone, not for your monitor: text that looks generous on a laptop is small on a handset held at arm’s length. If the video is for a feed, the large setting is usually right even though it looks oversized while you are editing.
- Keep lines short: a caption is read in a couple of seconds while something else is happening on screen. Lines are wrapped to fit the frame, and a caption that wraps to four lines is one that should have been split into two captions.