Burn Subtitles into Video Online — Free, No Upload
Hardcode SRT, WebVTT or ASS captions directly into your video so they show up everywhere — phones, TVs, social platforms, editors. Everything runs in your browser with FFmpeg: your video and subtitle file never leave your device. No upload, no registration, no watermark.
How to burn subtitles into a video
What does "burning subtitles" mean?
When you burn subtitles — also called hardcoding or embedding — the text is painted directly onto the video frames, becoming part of the picture itself. After burning, the captions are no longer a separate track you can turn off; they are as permanent as the image. This is different from a soft subtitle, which lives in a sidecar file or a separate stream that a player can show or hide on demand.
Burning matters because it guarantees the text appears regardless of what plays the file. A phone, a TV, a social-media uploader, an old media player, or a video editor that ignores sidecar subtitles will still show burned captions, because to them the captions are just part of the video. If you only ever watch on a capable Mac player, soft subtitles are more flexible — but for sharing and publishing, burned-in text is the safe choice.
Why burn subtitles into a video?
Make captions appear everywhere
The biggest reason is compatibility. Many platforms strip or ignore separate subtitle files. Baking the captions in means the viewer always sees them, with no extra step and no "subtitles not supported" message.
Share clips with friends and clients
When you send a short clip by message or email, a separate .srt is easy to forget or lose. A single self-contained MP4 with captions inside is far simpler to share and impossible to mismatch.
Post to social media and video sites
Most social platforms do not honour uploaded subtitle files the way you expect, or they require a specific caption-upload flow. Burning the text in sidesteps all of that: the captions are part of the footage, so they survive the upload.
Create accessible, on-screen transcripts
If you produce training, marketing or educational video, burned captions make the content accessible to viewers who are deaf or hard of hearing, and they help when someone is watching with the sound off — common on mobile feeds.
Lock a translation to the visuals
Burned subtitles keep the text perfectly aligned to the scene because they share the exact frame timing of the video. There is no separate track that could drift out of sync during playback.
Supported video and subtitle formats
This tool reads the video containers and caption files people actually use. Input subtitles are normalised internally to ASS for the burn step, so timing and text survive the conversion.
| Input video | Input subtitle | Burned output | Notes |
|---|---|---|---|
| MP4, M4V, MOV | SRT, VTT, ASS, SSA, SBV | MP4 (H.264) | Most common everyday formats |
| MKV, AVI, WebM | SRT, VTT, ASS, SSA, SBV | MP4 (H.264) | Re-encoded to a universally playable MP4 |
| FLV, OGV, TS/M2TS, 3GP | SRT, VTT, ASS, SSA, SBV | MP4 (H.264) | Legacy containers are repackaged |
| Any supported video | TXT (no timestamps) | Not on a timeline | TXT has no timing; convert to SRT first |
| Image-based (PGS/DVD) subs | Not accepted as a file | Use desktop | Bitmaps need OCR before burning |
The output is always an MP4 with H.264 video and AAC audio, capped at 1080p, which plays on essentially every device and platform. If you need to keep a specific codec or resolution, a desktop tool such as Total Video Player Pro for Mac gives you finer control.
Burn subtitles online vs. desktop software
Browser tools and desktop media software solve the same problem under different constraints. Here is the honest comparison.
| Need | This online burner | Desktop software |
|---|---|---|
| Install anything? | No | Yes |
| Upload file to a server? | Never | Not required |
| Burn SRT / VTT / ASS into MP4 | Yes, in-browser | Yes |
| Keep original resolution / codec | Capped at 1080p MP4 | Often yes |
| Batch many videos at once | One at a time | Often yes |
| Long 4K / multi-hour files | Slow, memory-limited | Faster, hardware-accelerated |
| Cost | Free, no limit | Paid or freemium |
For a short clip, a social video, or a one-off caption job, the online burner is the fastest path: no install, no upload, done in a few minutes. For nightly batch jobs, hour-long 4K footage or Blu-ray image subtitles, desktop software earns its place.
Common scenarios for burning subtitles
You make short videos for social media
Reels, Shorts and TikTok-style clips are watched muted more often than not. Burn your captions in and the message lands even with the sound off — and it survives the platform's compression.
You send clips to people who "never see subtitles"
Some players and message apps silently drop sidecar subtitles. A burned-in MP4 removes the guesswork: the text is in the picture, so it shows for everyone.
You publish tutorials or courses
Accessibility matters for training content. Burn the captions so every viewer, on every device, gets the transcript without hunting for a separate file.
You want a self-contained demo
A product demo with captions baked in is trivial to attach to a ticket, a chat, or an email — no instructions about "also download the subtitle file."
Privacy: your video never leaves your device
Every "burn subtitles online" service that uploads your file to a server creates a copy it could keep, scan or leak. This tool does not have that problem by design: there is no server in the loop. FFmpeg compiles to WebAssembly and runs inside your browser tab. Your video and subtitle file are read from disk into memory, the captions are painted onto the frames locally, and a download link is built locally. No network request ever carries your media.
The only network traffic is the page itself and, on first use, a one-time download of the FFmpeg engine (about 30 MB) that your browser then caches. Because burning re-encodes the video, the work happens on your own CPU — which is exactly why there is no upload wait and no server-imposed size limit. If you want proof, open your browser's network tab while using the tool: you will see no upload of your video.
Troubleshooting: when burning does not work
The burn starts but then fails
The source video may be damaged or truncated, or the subtitle file may be empty. Try a shorter clip or re-download the video, and confirm the subtitle file actually contains cues. Very large files above about 1.5 GB also push against the ~4 GB memory ceiling of a single browser tab; for those, desktop software is faster and more reliable.
"TXT cannot be burned" warning
A plain .txt transcript has no timestamps, so there is nothing to pin to the timeline. Open our Subtitle Converter, convert the TXT to SRT (or add timing in an editor), then burn the resulting SRT.
Characters look garbled (Chinese, Arabic, etc.)
Some subtitle files are saved in a legacy encoding such as Chinese GBK. This tool auto-detects UTF-8 and GBK and normalises the text to UTF-8 before burning, so captions usually render correctly. If you still see mojibake, re-save the source subtitle as UTF-8 in a plain-text editor first.
The burned video looks slightly soft
Burning forces a re-encode. This tool uses a high-quality H.264 setting and keeps resolution at or below 1080p, so for normal footage the difference is negligible. If you are burning a very high-bitrate 4K master, expect some softening — that is the trade-off of a browser tool versus desktop encoding.
The captions are too big or too small
Use the subtitle size control (Small to Extra large) before burning. The size is applied as part of the burn, so you can re-run with a different setting on the same files.
Frequently asked questions
Can I burn subtitles into a video online for free?
Yes. Load a video and a subtitle file (SRT, WebVTT, ASS, SSA, SBV or TXT), choose a font size, and the tool hardcodes the captions directly into the picture, then gives you an MP4 to download. There is no cost, no registration and no watermark.
Does this subtitles burner upload my video?
No. The entire process, including the re-encoding that burning requires, runs in your browser with the FFmpeg WebAssembly engine. Your video and subtitle file are read locally and never transmitted to any server, so there is no upload wait and no server-side size limit.
Which subtitle formats can I burn?
SRT, WebVTT, ASS, SSA, SBV and plain TXT are accepted. The tool normalises them to ASS for the burn step so timing and text are preserved. Note that TXT files have no timestamps, so they cannot be burned on a timeline — convert a TXT to SRT first if needed.
Will the burned subtitles play on any device?
Yes. Because the captions are part of the video frames, the resulting MP4 shows subtitles on every player, phone, TV and social platform — no separate subtitle file to keep track of and no player that refuses to show them.
Does burning subtitles reduce quality?
Burning is a visual change, so the video must be re-encoded. This tool uses H.264 at a high-quality setting and keeps resolution at or below 1080p, so the result looks virtually identical to the source for normal use. Very high-bitrate 4K sources may show slight softening.
Why not just keep subtitles as a separate file?
Separate subtitle tracks are great when the player supports them, but many devices, editors, social networks and screen-recording tools ignore sidecar subtitles. Burning them in guarantees they appear everywhere. For playback on a Mac with full styled-subtitle support, Total Video Player Pro for Mac plays external subtitle files without re-encoding.
Is there a limit on video length or size?
Because nothing is uploaded, the limit is your machine's memory, not a policy. A browser tab is capped at roughly 4 GB, so we warn above about 1.5 GB. Burning also re-encodes the video, which takes a noticeable fraction of the clip's own duration on a laptop — ideal for short clips and social videos, less ideal for multi-hour 4K files.
When to use a desktop player instead
This online burner is ideal for a quick, private, one-file job: you have a clip, you have subtitles, you want a self-contained MP4. It is not built for libraries. Each file is read into a single browser tab, large 4K or Blu-ray remuxes can hit the tab's memory ceiling, and there is no batch mode.
If you regularly work with long 4K footage, Blu-ray discs, or multi-track MKV on a Mac, Total Video Player Pro decodes them with hardware acceleration, shows every subtitle and audio track in a clean menu, and plays image-based PGS subtitles that a browser can never burn — with no re-encoding and no waiting. That is exactly the kind of work this free tool points you towards.
Burn subtitles every day on your Mac?
Total Video Player Pro for Mac plays MKV, AVI, Blu-ray and 4K HEVC with automatic multi-language subtitles, multiple audio tracks and playlists — no re-encoding, works offline, keeps your originals pristine.