How to Add Subtitles to a Video for Free (No Upload)
4 min read
Subtitles make your videos accessible, boost watch time on silent autoplay feeds, and help non-native viewers follow along. The problem: most caption tools either upload your video to a server, slap on a watermark, or charge per minute.
Here's how to add subtitles to a video completely free and privately — the speech-to-text runs in your own browser, so your video never leaves your device.
Step by step
- 1Open the free Auto Subtitles tool
Go to the Auto Subtitles tool. Nothing installs and there's no signup — it loads a small speech-recognition model into your browser the first time.
- 2Choose your video
Select the video file you want to caption. It stays on your device; the audio is transcribed locally using an in-browser Whisper model.
- 3Generate the captions
The tool extracts the speech and produces a list of timed caption lines automatically. This takes a moment depending on the length of your clip.
- 4Edit the text
Review the lines and fix any misheard words, names, or punctuation. Accurate captions matter for both viewers and SEO, so it's worth a quick pass.
- 5Download SRT/VTT or burn them in
Download a standard SRT or VTT subtitle file to upload alongside your video (YouTube, Vimeo, etc.), or burn the captions directly into the video for platforms that don't support subtitle files.
Tips
- For the most accurate transcription, use a clip with clear speech and minimal background music.
- SRT files let viewers toggle captions on/off; burned-in captions always show — best for TikTok, Reels and Shorts.
- Keep each caption line short (a few words) so it's readable on a phone screen.
Frequently asked questions
Is it really free to add subtitles?
Yes. The Auto Subtitles tool is free with no watermark and no signup. The transcription runs in your browser, so there's no per-minute charge like paid caption services.
Will my video be uploaded?
No. Both the speech recognition and the optional caption burn-in happen on your device, so your video is never uploaded to a server.
What's the difference between SRT and burned-in captions?
An SRT is a separate subtitle file viewers can turn on or off. Burned-in captions are permanently drawn onto the video, which is ideal for social platforms that always play muted.