Edit Subtitles in a Video

Work out where the subtitles are stored

Before changing anything, find out what kind of subtitles you're dealing with. It decides whether editing takes two minutes or needs a workaround.

A separate file

An .srt or .vtt file that travels with the video, or one you can download from YouTube Studio, Vimeo, a course platform or the person who made it. This is the easiest case.

A track inside the video file

Many MKV files and some MP4 files carry subtitles as a switchable track. The text lives in the file but not in the picture, and players list it in a subtitle menu.

Part of the picture

Burned-in, or hardcoded, subtitles were drawn onto the frames when the video was rendered. They appear in every player and can't be turned off, because they're pixels like the rest of the image.

A quick test: open the video in a player such as VLC and look at its subtitle menu. If you can switch the subtitles off, they're a track or a sidecar file. If they stay on screen whatever you choose, they're burned in.

Case one: you have the subtitle file

1. Open the editor on this page and choose the video. Switch off "Write the subtitles automatically with AI" since you already have text.
2. Click Import SRT / VTT and pick the file. A notice reports how many lines were read and whether any blocks were skipped.
3. Play the video and read along. Click a row, or press Up and Down, to jump between lines, and type corrections straight into the text box. Press Enter inside a text box to start a second line within the same subtitle.
4. Fix any line that appears early or late by dragging its edges on the timeline or typing a new time into the row.
5. Check the warnings under each row, then click Export SRT or Export VTT to replace the old file, or Render video for an MP4 with the corrected subtitles in the picture.

Two things change on the way through. Formatting tags in the imported file, such as italics, colour and position codes, are dropped, because one style applies to the whole video. And on export, lines with no text or no duration are left out, so the numbering in the new file may differ from the old one.

The exported file takes the video's name, which most players need to pick it up automatically.

Case two: the subtitles are a track inside the file

The editor reads only the picture and sound of a video, not the subtitle tracks stored alongside them, so the text has to come out of the container first. Two free tools are common for this:

• FFmpeg can copy a text track to an SRT file. A typical command is ffmpeg -i film.mkv -map 0:s:0 film.srt, where 0:s:0 means the first subtitle track; change the number for the second or third.
• MKVToolNix includes mkvextract, which pulls tracks out of MKV files without re-encoding anything.

Some tracks are images rather than text, notably PGS subtitles from Blu-ray discs and VobSub from DVDs. Extracting them gives you pictures of words, which need optical character recognition before they can be edited. Desktop programs such as Subtitle Edit include OCR for this.

Once you have an SRT, follow case one. Afterwards you have a choice: keep the corrected subtitles as a separate file, put them back into the container as a track with MKVToolNix or FFmpeg, or render them into the picture here. The editor itself doesn't write tracks into files. Adding subtitles to an MKV covers that format's quirks in more depth.

If the subtitles you want to change are YouTube's own captions on a published video, the edit belongs in YouTube Studio rather than in a file; editing YouTube auto captions explains that route.

Case three: the subtitles are in the picture

Burned-in subtitles can't be edited as text, here or anywhere else, because the original letters are gone and only coloured pixels remain. What you can do is hide them and draw new ones.

• Ask for a clean copy. Whoever made the video may have a version without text, often called a textless master. That gives a far better result than any cover-up, and textless video versions explains what to ask for.
• Blur the old strip. In the Style tab, under Original subtitles, turn on "Hide subtitles already in the video". A blurred band appears near the bottom; drag "Band position" and "Band height" until it covers the old text. The blur applies to every frame and your new subtitles are drawn on top.
• Get the new words. The old on-screen text isn't read. Instead, let AI transcribe the speech, import a corrected SRT, or type the lines yourself.

The band blurs everything inside it, not only the letters, so keep it as thin as the old subtitles allow. If the old subtitles sometimes jump to the top of the frame, one band can't follow them. Hiding burned-in subtitles goes further into band placement.

When something goes wrong

• "No subtitles found in that file": the file isn't SRT or VTT. ASS and SSA files can be converted with FFmpeg (ffmpeg -i old.ass new.srt) or a desktop subtitle tool, then imported.
• Accented letters show as symbols: the file was saved in an older text encoding. Re-save it as UTF-8; subtitles showing strange characters explains why it happens.
• Every line is late by the same amount: type the offset into Shift all by. A negative number moves lines earlier.
• Lines start in sync and drift: that points to a frame-rate mismatch, which retiming individual lines helps with.
• Some blocks were skipped on import: those blocks had no readable timing line. Open the file in a text editor and check that each block has a line with two times separated by an arrow.

Variations on the job

If you only need to change words and your audience uses a player that loads files, there's no reason to re-render the video: export the corrected SRT and replace the old one. The SRT editor page focuses on that file-only workflow.

If the video needs subtitles in a different language, translation here works from the speech rather than from the existing file. Turn on AI subtitles, choose a Subtitle language, and review the result. For a subtitle file in another language without opening the editor, use translated subtitles, or start from scratch with the AI subtitle generator.

If the subtitles are fine and only the look is wrong, skip straight to the Style tab; the editor overview lists every control.

About the subtitle editor on this page

Opens

MP4, MOV, M4V, WebM, MKV videos your browser can decode

Subtitles from

AI (from the speech, optionally translated into one of 21 languages), an SRT or VTT file, or typing them in

You download

An MP4 with the subtitles drawn into the picture at the original resolution and frame rate, plus SRT and VTT files

Cost

Editing, styling, rendering and SRT/VTT export are free, with no account and no watermark. AI subtitles cost 1 credit per minute (5-credit minimum per video); signing in with Google gives 100 free credits and accounts get 10 free credits a day

Privacy

The video never leaves your device and is rendered in your browser. Only for AI subtitles is the audio sent, over HTTPS, and it is deleted within 30 minutes of delivery

Rendering needs

Chrome or Edge 94+, Safari 16.4+, or Firefox 130+ on a computer. Editing and SRT/VTT export work in any current browser