Free tool
Add subtitles to MP4
Bring the MP4 and its SRT or VTT to add subtitles to MP4 files two ways: burned into the picture, so the captions show wherever the video is posted, or as a subtitle track inside the MP4, which QuickTime Player and Safari can switch on and off.
- Free
- Burned in, or a track
- Nothing is uploaded
1. The video
Drop your MP4 video here, or Choose your MP4 video
MP4, MOV, WebM or MKV, up to 2 GB and 3 hours. Everything happens in your browser; nothing is uploaded.
2. The subtitles
SRT, VTT, SBV or ASS. No subtitles yet? Make them from the video with the subtitle generator.
How it works
How do you put an SRT into an MP4?
Choose the MP4 and the SRT. For a video you’ll post or send, keep Burned in, check a caption in the preview and press Burn in subtitles. For a file people will watch in QuickTime or Safari, choose Subtitle track, pick the language and press Add subtitle track.
- 1
Choose the MP4 and the SRT
To add SRT to MP4, choose both; a VTT, SBV or ASS file works too, including a Zoom or Teams transcript in VTT.
- 2
Burned in or a track
Burned in re-encodes the picture as H.264; a track copies the video and adds the captions beside it.
- 3
Download the MP4
It keeps the video’s name with “-subtitled” added; the original MP4 and SRT stay as they were.
Which players show an MP4 subtitle track?
Apple’s. The track is WebVTT, the subtitle format the web and Apple use: QuickTime Player and Safari on a Mac list it under Subtitles by its language. Chrome doesn’t show tracks inside a video, and players built on FFmpeg don’t read this kind.
- QuickTime Player, Safari (Mac)
- Shows the trackYes, as a subtitle option named after its language
- Chrome, Edge
- Shows the trackNo
- Social sites and chat apps
- Shows the trackNo; burn the captions in
| Player | Shows the track |
|---|---|
| QuickTime Player, Safari (Mac) | Yes, as a subtitle option named after its language |
| Chrome, Edge | No |
| Social sites and chat apps | No; burn the captions in |
Can you subtitle a Zoom or Teams recording?
Yes. Both save meetings as MP4, and both can save a transcript as a VTT file; bring the two here. Speaker names in the VTT can be shown at the start of each caption (“Maya: …”) or left out, with the Show speaker names box.
Where do the subtitles come from if the recording has none?
From a transcript. NoteOwl imports the MP4 on your Mac, transcribes it with each speaker named and saves it as SRT; or the subtitle generator makes one in the browser. Either way, bring the SRT back here.
FAQ
Questions about adding subtitles to an MP4
Is my MP4 uploaded?
No. The MP4 and the SRT are read from your device and the new MP4 is made in the page. In our tests no network request left the browser while it worked.
Does adding a subtitle track re-encode the video?
No. The H.264 or HEVC video and the sound are copied as they are, and the captions are added beside them, so it takes seconds. Only burning in re-encodes the picture.
Can I turn burned-in subtitles off later?
No, they’re part of the picture. Keep the original MP4 and the SRT; if the captions need changing, fix the SRT and burn them into the original again.
Why can’t some players see the subtitle track?
Players read different kinds of MP4 subtitle track. This one is WebVTT, which QuickTime Player and Safari show, but players built on FFmpeg don’t read it. For those, choose MKV under Save as: the captions go in as an SRT track, which FFmpeg reads.
Do the captions keep italics?
In a subtitle track, yes, the italic and bold tags are kept. Burned-in captions are drawn in one style; a caption in italics throughout is drawn in italics.
What size and position are the burned-in captions?
Medium, at the bottom on a dark box, unless you choose otherwise: small, medium or large, a box or an outline, at the bottom or top. The text scales with the video, so it looks the same on a phone video and a 4K one.
Keep exploring
Add subtitles to video
- Add subtitles to MOVBurn subtitles into an iPhone or QuickTime MOV in your browser, upright on portrait videos, and keep it a MOV
- Add subtitles to WebMBurn subtitles into a WebM in your browser (re-encoded as VP9), or keep them separate as a VTT for a web page’s video
- Add subtitles to videoBurn an SRT, VTT or ASS file into a video, or add it as a subtitle track, in your browser; long lines, two-line captions, any script, right to left
Related
- Subtitle converterConvert subtitles between SRT, VTT, SBV and ASS, or to plain text, in your browser; SSA scripts and meeting transcripts work too
- Video to textTurn video to text free: drop in an MP4, MOV, M4V, MKV or WebM video and get an AI transcript with times, as text, SRT, VTT or Word; only the sound is sent, nothing is stored
- What is an SRT fileWhat an SRT file is, what SRT stands for, the format of each cue with an example, and how to make one from a recording
Recordings to subtitles, on your Mac
Free to download. Runs entirely on your Mac.
macOS 26 or later · Apple Silicon (M1 or newer) · 16 GB memory minimum, 24 GB recommended
About NoteOwl
NoteOwl is private AI meeting notes and memory for the Mac. It captures meetings without a bot joining the call, labels every speaker, writes summaries and action items, and builds a memory of every conversation that you can chat with — fully offline, because the speech recognition and the AI run on the Mac itself. Dictation into any app is free; Pro is a one-time purchase.
NoteOwl pricing: what’s free and what Pro adds
Last updated
Which way works for social media?
Burned in. A video posted to a feed or sent in a chat is played as picture and sound; a subtitle track inside the file is ignored. Many people watch with the sound off, so burned-in captions carry the words in every feed.
Where a site lets you upload an SRT beside the video, as YouTube does, uploading the SRT keeps the captions switchable. Burning in is for everywhere else.