How do I add subtitles to a video?

Drop the video into the top box, choose your .srt, .vtt or .ass file under Subtitle file, pick how to add them and press Add subtitles. You download one MP4 with the subtitles in it.

What is the difference between burned-in and a selectable track?

Burned-in subtitles are drawn into the picture, so they show everywhere and cannot be turned off. A selectable track is a separate stream in the file that a player can show or hide, and the picture stays untouched. Some players and sites ignore embedded tracks.

Which subtitle formats can I use?

SRT, WebVTT (.vtt) and ASS or SSA files. To change one format into another before adding it, use the SRT to VTT converter.

Why do my subtitles show as empty boxes?

The font used for burned-in text covers Latin letters only. Languages written in other scripts need the selectable track option, which keeps the text and lets the player use its own fonts.

My subtitles do not match the video. What is wrong?

Check the line the page shows under the video: it says when the last subtitle ends. If that is far from the video's length, the file probably belongs to a different version of the video. This tool does not shift timing.

Can I change the size, colour and position of the text?

Yes, for burned-in subtitles: small, medium or large, white, yellow or cyan, bottom, middle or top, with an optional dark box behind the text. A selectable track is drawn by the player, so these settings do not apply to it.

Does adding subtitles reduce the video quality?

Burning them in re-encodes the picture at a high quality setting, because the text must be drawn on every frame. A selectable track copies the picture as it is for MP4, MOV and M4V videos.

Is my video uploaded, and is it free?

Nothing is uploaded. The video and subtitles are processed in your browser with a WebAssembly build of FFmpeg, and only the engine and a font file are downloaded. It is free, with no watermark, no account and no limit.

Add Subtitles to Video — Burn In SRT or Add a Track

Add subtitles to a video online: burn an SRT, VTT or ASS file into the picture or add it as a selectable track. Free, no upload, in your browser.

Last updated: 8 October 2026

Drop a file here or click to browseMP4, MOV, WebM, MKV, AVI — the video to add subtitles to🔒 Processed on your device — never uploaded

Subtitle file(required)

SRT, WebVTT or ASS. Need to change the format first? Use the SRT to VTT converter.

How to add them

Burned-in text supports Latin letters (English, Spanish, French, German and similar). For other scripts, use the selectable track.

Text size (burned in)

Text colour (burned in)

Position (burned in)

Dark box behind the text (burned in)

Easier to read over busy pictures.

Language of the track (selectable track)

Was this tool useful?

Use the tool above and you can rate it here.

Put subtitles on your video

Choose a video and a subtitle file, decide whether the text is drawn into the picture or added as a track that viewers can switch on and off, and download one MP4. You can set the size, colour and position of burned-in text. Everything happens in your browser, so the video and your subtitles are never uploaded.

Burned in or a selectable track

Burned in means the words become part of the picture. They show on every player and every site, and nobody can turn them off, which is why it is the safe choice for sharing. A selectable track keeps the subtitles as a separate stream inside the MP4, so a player can show, hide or switch them, and the picture is not touched. Not every player or browser shows embedded tracks, so check where yours will play.

Size, colour and position

Burned-in text can be small, medium or large, white, yellow or cyan, and placed at the bottom, middle or top. A dark box behind the text keeps it readable over busy pictures. The size is relative to the height of the video, so the same setting looks the same on a small clip and on a full HD one.

Languages and fonts

Burned-in text uses the Geist typeface, which covers Latin letters: English, Spanish, French, German and similar languages. Scripts such as Hindi, Arabic, Chinese or Cyrillic would show as empty boxes, so for those choose the selectable track, which stores the text itself and lets the player draw it with its own fonts. Files that are not saved as UTF-8 are read as Windows-1252, and the page tells you when that happens.

Timing and checking

After you choose the file, the page shows how many subtitles it holds and when the last one ends, and warns you if that is after the end of the video or far short of it, which usually means the file belongs to a different video. This tool does not shift timing. If you need a different format first, use the SRT to VTT converter, and to shrink the result afterwards use the video compressor.

Frequently asked questions

How do I add subtitles to a video?: Drop the video into the top box, choose your .srt, .vtt or .ass file under Subtitle file, pick how to add them and press Add subtitles. You download one MP4 with the subtitles in it.
What is the difference between burned-in and a selectable track?: Burned-in subtitles are drawn into the picture, so they show everywhere and cannot be turned off. A selectable track is a separate stream in the file that a player can show or hide, and the picture stays untouched. Some players and sites ignore embedded tracks.
Which subtitle formats can I use?: SRT, WebVTT (.vtt) and ASS or SSA files. To change one format into another before adding it, use the SRT to VTT converter.
Why do my subtitles show as empty boxes?: The font used for burned-in text covers Latin letters only. Languages written in other scripts need the selectable track option, which keeps the text and lets the player use its own fonts.
My subtitles do not match the video. What is wrong?: Check the line the page shows under the video: it says when the last subtitle ends. If that is far from the video's length, the file probably belongs to a different version of the video. This tool does not shift timing.
Can I change the size, colour and position of the text?: Yes, for burned-in subtitles: small, medium or large, white, yellow or cyan, bottom, middle or top, with an optional dark box behind the text. A selectable track is drawn by the player, so these settings do not apply to it.
Does adding subtitles reduce the video quality?: Burning them in re-encodes the picture at a high quality setting, because the text must be drawn on every frame. A selectable track copies the picture as it is for MP4, MOV and M4V videos.
Is my video uploaded, and is it free?: Nothing is uploaded. The video and subtitles are processed in your browser with a WebAssembly build of FFmpeg, and only the engine and a font file are downloaded. It is free, with no watermark, no account and no limit.