Burn Subtitles Into Video (Hardcode SRT, VTT, ASS)
Burn subtitles into video so they show on every screen, including Instagram, TikTok and WhatsApp, which ignore subtitle tracks. Drop the video with its SRT, VTT or ASS file, pick an outline, box or shadow look, a font, size and position, and download the result. Rendering uses your graphics hardware in the browser; nothing is uploaded and there is no watermark.
- Runs on your device
- WebCodecs · GPU
- Canvas · GPU
- Works offline
Updated
Drop your video and subtitle file here
How to burn subtitles into a video
Step 1: Add the clip plus its SRT, VTT or ASS in one drop. If you add only the video, attach the captions with the Subtitle file option.
Step 2: Pick a Style (Outline, Boxed or Shadow), a Font, the Size and the Position.
Step 3: Press Burn. Every frame is redrawn with the text, so this takes about as long as a normal export.
Step 4: Download the video. It keeps your original format when that is MP4, MOV, MKV or WebM; anything else becomes MP4.
Good to know
Settings explained
- Subtitle file
- SRT, VTT, ASS or SSA — or drop it together with the video.
- Size
- Relative to the shorter side of the video (the height for landscape).
- Quality
- Only used when a stream has to be re-encoded. Compatible streams are copied with no quality loss.
- Faster: Smaller file, quickest export
- Balanced: Good quality at a sensible size
- Best quality: Largest file, slowest export
Formats
Combines several files into one result.
How it runs
- Hardware video engine
- Video is decoded and encoded by your device’s media hardware through WebCodecs — usually several times faster than real time.
- GPU canvas
- Pixels are drawn and composited with the GPU-accelerated canvas.
- FFmpeg (when needed)
- Older formats and a few filters use FFmpeg compiled to WebAssembly. It downloads once (about 31 MB) the first time it is needed and is cached for offline use.
Hardsub vs softsub: which one you need
Burned-in (hard) subtitles are pixels in the picture: always visible, never switchable. Soft subtitles are a track the viewer turns on. Choose by where the video will be watched. If you have no subtitle file yet, auto captions can write and burn one in a single step.
| Burned in (this page) | Soft track | |
|---|---|---|
| Shows on Instagram, TikTok, WhatsApp, Stories | Yes | No |
| Viewer can turn it off or change language | No | Yes |
| Your font, colour and box | Yes, exactly as you set it | Up to the player |
| Picture re-encoded | Yes, every frame | No, streams are copied |
| Can be removed later | No, keep your original | Yes |
| Tool | Burn subtitles into video | Add subtitles to video |
What are hardcoded subtitles?
Hardcoded subtitles (also called burned-in subtitles, hardsubs or open captions) are subtitles drawn permanently into each frame of the video. Because they are part of the image, every player and app shows them, but nobody can switch them off, resize them or swap the language afterwards.
That permanence is the point for social media, where most people watch muted and apps throw away subtitle tracks.
How big the text will be
The Size setting is a percentage of the video’s shorter side, so a vertical 1080×1920 clip and a landscape 1920×1080 clip get the same text height. These are the pixel heights the renderer uses:
| Video | 3% | 4.5% (default) | 6% | 8% |
|---|---|---|---|---|
| 720p (1280×720) | 22 px | 32 px | 43 px | 58 px |
| 1080p or vertical 1080×1920 | 32 px | 49 px | 65 px | 86 px |
| 4K (3840×2160) | 65 px | 97 px | 130 px | 173 px |
Burn SRT or ASS: what the renderer keeps
- SRT, VTT, SBV and other text formats are drawn by ProMedia’s own renderer on your graphics chip: no download, audio copied untouched. Italics, bold, inline colours and
{\an8}top placement are honoured, and lines that overlap in time are stacked. - ASS and SSA files keep their own colours, sizes, positions and effects when Use ASS styles when present is on. They are rendered with libass in the FFmpeg engine (downloaded once), fonts are replaced by Inter and the result is an H.264 MP4.
- Arabic, Hebrew, Hindi, Thai, Chinese, Japanese and Korean text is always drawn with the built-in renderer, which can use your system’s fonts for those scripts; your Style, Font and Size choices apply, even to ASS files.
Tips & troubleshooting
Timing off? Fix the file with subtitle sync before burning; burned text cannot be retimed afterwards.
Typos are permanent once burned. Check the lines first in the subtitle editor online.
Keep the original video and the subtitle file. To change a word later you burn again from those, not from the result.
Boxed text stays readable over bright, busy footage; Outline looks cleaner on darker scenes.
Burn Subtitles (Hardsub) FAQ
What does burn-in subtitles mean?
It means the subtitle text is drawn into the video frames themselves, the way a title or logo is. The result is a normal video file whose picture contains the subtitles, so they appear in any player and cannot be turned off.
How do I add subtitles to a video permanently?
Drop the video and its SRT here, choose a style and press Burn. The text becomes part of the picture. To add them permanently but switchable, store them as a track with add subtitles to video instead.
Can I burn subtitles without VLC or HandBrake?
Yes. This page does the same job in the browser on Windows, Mac, Linux or ChromeOS with nothing to install, and it shows the style options up front. HandBrake is still useful for very long batch encodes.
Does burning subtitles lower the quality?
The picture is re-encoded once, as with any export. At Balanced quality (under Advanced settings) the difference is hard to see; pick Best for archive copies. Audio is copied unchanged when the built-in renderer is used.
Is your video uploaded anywhere?
No. Your video is processed by your own browser on your own device. There is no server that receives files, so nothing is uploaded, stored or shared. You can even switch to airplane mode once the page has loaded.