Subtitle Adder
Add subtitles and captions to videos
Your files are processed on your device. The first use downloads a processing engine, which your browser then keeps.
Drop a videoTap to choose a video
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Add subtitles and captions
Large files (over 5 GB) may take longer or run out of browser memory
About Subtitle Adder
Burns subtitle text into a video's picture (or, if you tick the option, adds it as a switchable subtitle track), using standard SRT-format timing, in English and in Hindi, Tamil, Telugu, Bengali, Gujarati, Kannada, Malayalam, Punjabi, Arabic, Hebrew, Thai and other scripts (Chinese, Japanese and Korean are not supported yet). Runs entirely in your browser — the video never leaves your device.
Upload your video, paste your subtitles in SRT format (the standard "1 / 00:00:00,000 --> 00:00:05,000 / Hello, world!" style), and download the video with subtitles burned in.
Burning subtitles into the picture forces a full re-encode of the video, so this takes real time and burned-in subtitles can no longer be turned off or edited afterward — if you might need to change the captions later, keep your original SRT file safe as well. Some phone-recorded videos (particularly .mov files) use a codec this tool can't read — if processing fails right away, try re-exporting the video from your phone's own share options first. In the subtitle-track option, any text in angle brackets such as <Tags> is read as formatting markup and removed from the track, so write it without the brackets if it must show.
Watch: Subtitle Adder in Action
- Can I turn subtitles off after adding them?
- No — this burns subtitles directly into the video's picture permanently. If you might need to change or remove the captions later, keep your original SRT file saved separately as well.
- What subtitle format does this accept?
- Standard SRT format — the common "1 / 00:00:00,000 --> 00:00:05,000 / Hello, world!" style timing that most subtitle editors and video tools export.
- Are the subtitles burned in or added as a track?
- Burned in by default, which draws the words into the picture permanently. If you tick the option to add a subtitle track, they are stored as a separate, switchable track instead, as long as the video's formats allow it.
- Which subtitle files can I upload?
- You can paste SRT text or upload .srt, .vtt, .ass or .ssa files. WebVTT and ASS or SSA are converted to plain SRT, so styling inside ASS files is dropped and only the text and timing are used.
- Does it support Hindi, Arabic or Chinese?
- Latin text plus Hindi, Tamil, Telugu, Bengali, Gujarati, Kannada, Malayalam, Punjabi, Arabic, Hebrew, Thai and other scripts work. Chinese, Japanese and Korean are rejected with a message, because their fonts are too large to bundle.
- Why did it burn the subtitles in when I asked for a track?
- A separate track needs the video and audio to fit an MP4 without re-encoding. If the codecs do not qualify, such as with some WebM files, the tool shows a notice and falls back to burning the captions into the picture.
- What does the error about a line number mean?
- The tool checks your SRT before processing. It reports the line where a time such as 00:00:01,000 --> 00:00:04,000 is missing or malformed, or where the end time is not after the start time. Fix that line and try again.
How to use Subtitle Adder
Drop a video, then paste your subtitles into the Subtitle Text box in SRT form, with a number, a time line such as 00:00:01,000 --> 00:00:04,000 and the text. Alternatively choose Or upload an .srt, .vtt or .ass file, and WebVTT or ASS files are converted to SRT text for you. A mistake is reported by line number.
Use Size (Small, Medium, Large), Position (Bottom, Middle, Top), Colour (White, Yellow) and the Dark box behind text checkbox to style the captions. By default they are burned into the picture. Tick the subtitle-track option instead to add a separate, switchable track. Press Add Subtitles and download subtitled_ plus your name as an MP4.
When to use it
Burning captions in is the right choice for clips to be shared on platforms that ignore subtitle files, such as social posts and messaging apps, where the words must always show. The separate track option suits a video you will play locally or upload somewhere that reads tracks, since viewers can turn it off.
When not to use it
It does not write captions for you or sync them to speech; you must supply the timings. Chinese, Japanese and Korean text is not supported and raises an error. For several language tracks in one file, or styled karaoke effects, a full video editor is the proper tool. A separate track is not suitable for platforms that discard them.
Tips for best results
Test your SRT with a short clip first, because a burn-in re-encodes the entire video. Style options apply only to burned-in captions. Keep the SRT file safe, since burned-in words cannot be edited later. Hindi, Tamil, Arabic, Thai and other supported scripts use their own bundled fonts, so you do not need those fonts installed.
Limitations
In the separate track option, any text in angle brackets such as <Tags> is read as formatting markup and removed from the track; write it without the brackets if it must show. Burning in always produces an MP4 and re-encodes the video with H.264 and AAC, so it takes real time. The track option works only when picture and sound can go into MP4 untouched (H.264, HEVC or MPEG-4 video with AAC, MP3 or AC-3 audio, or no audio); otherwise the tool burns the captions in and tells you. The track is labelled English whatever the text language, and styling is not applied.
Privacy
Your video and your caption text stay in the browser tab. Captions are turned into an ASS file, or into image strips for Indic and Arabic scripts, on your device. The fonts, Roboto and the Noto script fonts, are requested from this site's own server, and the engine, about 25 MB, from a public CDN, but neither request contains your footage or words.
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