Free browser tool
Add Subtitles to Video
Generate captions from speech automatically, edit the wording, style them to match your brand, and burn them straight into your video. Everything runs privately in your browser.
- Automatic transcription
- No upload
- No sign-up
- No watermark
Drop a video here or click to browse
MP4, MOV, WebM, AVI — transcribed and rendered locally in your browser
Sponsored by the makers
Tired of boring screen recordings?
Try Screen Charm.
Auto-zoom, motion blur, camera overlay, and background music. All built in. Record once, export a polished video.
See what it doesHow to add subtitles to a video online
Drop your video
Select any MP4, MOV, WebM, MKV, or AVI file. Nothing is uploaded — the file is read straight from your device.
Generate the subtitles
Speech recognition runs in your browser and turns the audio into timed caption lines, split at natural pauses.
Edit and style
Fix any wording, retime lines, then choose a font, size, colour, outline, and position with a live preview.
Render the MP4
The captions are burned into the picture and you get an MP4 ready to post, plus optional SRT and VTT files.
Caption styles you can control
Captions are rendered with the same subtitle engine used by professional video tools, so outlines, shadows, and background bars stay crisp at any resolution. Start from a preset and adjust anything you like — the preview shows the result before you render.
Typography
Four caption-grade fonts, text size, bold, italic, uppercase, letter spacing, and how many characters fit per line.
Readability
Outline width and colour, drop shadow, or a solid background bar with adjustable opacity for busy footage.
Placement
Top, middle, or bottom of the frame, left/centre/right alignment, and a margin slider to clear on-screen UI.
When to add subtitles
Social videos that play muted
Most feeds autoplay without sound. Burned-in captions mean your message lands even when the viewer never turns the audio on.
Product demos and tutorials
Captions make dense walkthroughs far easier to follow, especially when you are naming menus, buttons, and keyboard shortcuts.
Accessibility and compliance
Captions are a baseline accessibility requirement. Generate them in minutes instead of typing a transcript by hand.
Non-native audiences
Readers who find a spoken accent hard to follow can read along, which measurably improves completion rates on longer videos.
Confidential recordings
Because nothing is uploaded, you can caption internal demos, customer calls, and unreleased product footage safely.
Repurposing long recordings
Export an SRT and reuse it as a transcript, a blog outline, or chapter markers for the same recording.
Frequently Asked Questions
How do I add subtitles to a video for free?
Drop your video into the tool and click Generate subtitles. Speech is transcribed on your device, then you can fix any wording, pick a caption style, and click Add subtitles to video to render an MP4 with the captions burned in.
Are the subtitles generated automatically?
Yes. The tool runs an OpenAI Whisper speech recognition model directly in your browser and splits the transcript into readable caption lines with timings. You can then edit any line before rendering.
Is my video uploaded to a server?
No. Both the speech recognition and the video rendering happen locally using WebAssembly. Your video and its audio never leave your device, which also means the tool works on confidential recordings.
Can I change the subtitle font, size, and position?
Yes. You can choose the font, text size, colour, outline width and colour, drop shadow, background box, letter spacing, line length, horizontal alignment, and whether captions sit at the top, middle, or bottom of the frame. Six ready-made presets cover the most common looks.
Can I edit the subtitle text after it is generated?
Yes. Every line is editable. You can rewrite the text, adjust the start and end time, split a line in two, merge it with the next one, or delete it entirely. The preview updates as you type.
What is the difference between burned-in subtitles and an SRT file?
Burned-in subtitles are permanently part of the video image, so they always show and cannot be switched off — ideal for social media where captions are expected. An SRT or VTT file is a separate text file that players and platforms can toggle on or off. This tool can produce both.
Which languages are supported?
The Whisper model is multilingual and covers major languages including English, Spanish, French, German, Italian, Portuguese, Dutch, Russian, Polish, Turkish, Japanese, Korean, Chinese, Hindi, and Arabic. Leave the language on Auto-detect or pick one to improve accuracy.
Why does the first run take longer?
The speech model and the video engine download once, then your browser caches them. The first video therefore takes longer to start than every run after it. Transcription and rendering speed depend on your computer, since all the work happens locally.
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Sponsored by the makers
Tired of boring screen recordings?
Try Screen Charm.
Auto-zoom, motion blur, camera overlay, and background music. All built in. Record once, export a polished video.
See what it does