Burn SRT subtitles into a video
Your SRT or VTT file drawn permanently into the picture, so the subtitles show in every player and app.
- Nothing is uploaded
- Works offline after first use
- Open source
- No watermark. On a phone, a video over about 200 MB (2 minutes of iPhone video) may run out of memory
Burns an SRT or VTT subtitle file permanently into an MP4, MOV or WebM video, in the look, size and place you pick, and saves a new MP4. It is free, needs no account and adds no watermark, and your files are not uploaded: the video is re-encoded in your browser, and your own subtitle file needs no model. If you drop only the video, a speech model (76 MB) downloads once to write the subtitles, and the longest video you can burn depends on your device’s memory.
Your iPhone may take a few seconds to prepare the video first, longer if it's stored in iCloud.
Done
Open the network tab. Your files never appear in it.
Add files and run the tool to see every request this tab makes.
Your files are processed on this device and never sent to a server. Reload the page to clear everything from memory.
A separate subtitle file only works where the player looks for it. Messaging apps, most social platforms and many TVs play the video alone, so the subtitles vanish. Burning them in, also called hardcoding or open captions, draws the words into the picture itself. This page takes the SRT or VTT file you already have, from a translator, a subtitle site or Video to subtitles, and burns it into the video.
A worked example: a 3-minute interview.mp4 in 1920×1080 and the Spanish translation interview.es.srt from your translator. Drop both files together. The SRT is read as it is, with no speech model and no download. White on a dark band is already chosen, which keeps text readable over any footage, and on a 1080p video Medium sets the text at about 70 pixels. Each caption is wrapped to fit the frame, at most two lines, and appears exactly on its timing. You get interview-subtitled.mp4 with the sound carried across.
The timing comes straight from the file. If the subtitles run early or late, the SRT was made for a different cut of the video; burning in cannot fix that, so correct the times in a subtitle editor first. Styling written into the file, such as italics or colour tags, is dropped so every caption uses the look you chose.
How it works
- Drop the video and its SRT or VTT file together.
- Pick the look, size and place of the subtitles.
- Press Burn in subtitles. Every frame is drawn with its caption and the new video downloads.
In your browser, not on a server
Without a subtitle file, the soundtrack is transcribed exactly as in Transcribe: decoded in your tab at 16 kHz, cut at pauses, and timed by OpenAI’s Whisper base model (MIT) running in a background worker through transformers.js (Apache-2.0) and onnxruntime-web (MIT). With an SRT or WebVTT file, its captions are read as they are. Each caption is wrapped to fit the width of the picture, two lines at most, and a long one becomes several in a row. Mediabunny (MPL-2.0) then decodes the video, every frame is drawn on a canvas with the caption that is due, and your browser’s own video encoder (WebCodecs) writes a new MP4, with the sound copied across.
Compared with upload-based tools: Online captioning apps upload the whole video, cap free minutes, and many stamp their logo on the result or keep it for training. Here the video and its words stay on your device, with no watermark and no minute limit beyond your device’s memory (phones hold less).
Verify it yourself. Give the page a short while after your first run to save itself for offline use, then turn off Wi-Fi or switch to airplane mode and run the tool again. Or open your browser's developer tools (F12, or Cmd-Option-I on a Mac), pick the Network tab, and watch it while you convert. The panel above does the same count for you.
Questions
What if I do not have a subtitle file?
Drop only the video and the subtitles are written from the speech by a model running in this tab. To check the words first, tick Also save the subtitles as an SRT file, correct it, and run again with the fixed file.
Can I keep the subtitles as a track viewers can turn off instead?
Not here: this page draws them into the picture. Players such as VLC load an SRT with the same name as the video, and YouTube accepts the SRT as an upload in Studio.
Which subtitle formats work?
SRT and WebVTT (.vtt). ASS and SSA files with positioned or animated styles are not read; convert them to SRT in a subtitle editor first.
What is the difference between burned-in and soft subtitles?
Burned-in subtitles (also called hardcoded or open captions) are drawn into the picture, so they show in every player and cannot be turned off. Soft subtitles are a separate file or track that a player can show or hide. This page makes burned-in ones; for a separate SRT file, use Video to subtitles.
How do I make the SRT file in the first place?
Use Video to subtitles: it writes an SRT from the speech in the video, which you can correct and then burn in here.
Can I burn subtitles into a video without uploading it?
Yes. The subtitle file is read and the video re-encoded by your browser, on your device. Neither file leaves it.
Do I need an account, and is there a watermark?
No account and no sign-up: open the page and drop a file. Nothing is added to your file, so there is no watermark or logo. It is free, and your files are not uploaded.
More video and audio tools
Add subtitles to video
Captions written from the speech and burned into the picture, on your own device. Or bring an SRT and burn in that.
Transcribe audio to text
Speech to text and subtitles made by an AI model running in this tab. Interviews, lectures and voice notes are never uploaded.
Vocal remover
Split a song into the music and the voice with an AI model running in this tab. Karaoke tracks and acapellas without uploading anything.
Video background remover
The person stays, the room goes: blurred, a flat colour or a picture of your choice, done frame by frame on your own device.
Other conversions
Guides
- How to add subtitles to a videoCaptions written from the speech and burned into the picture, without a watermark or a length cap. Here is how, and a tool that does both steps on your own device.