Auto caption generator
Turn what's said in a video into timed captions, for free: edit them, download SRT or VTT, or burn them into a vertical video. It runs in your browser, so your video is never uploaded.
MP4, MOV, WebM, MP3 or WAV, or drop one on the player. It's transcribed on your device: nothing is uploaded.
An example: 8 seconds of IMPAULSIVE
Free, with nothing to sign up for. The speech model is a one-time download of about 76 MB; after that it's kept in your browser.
How to generate captions for a video
- Choose your video or audio file, or drop it on the player. Pick a part if you don't need all of it.
- Pick the language and how long each caption should be: a few words at a time for TikTok, Reels and Shorts, or full subtitle lines for YouTube.
- Generate the captions, play the video to see them, and fix any word that's wrong.
- Download an SRT or VTT file, or burn them into a vertical video in the 5 caption styles clips use.
A few words at a time, or full subtitle lines?
| Captions | Each one | For |
|---|---|---|
| A few words at a time | Up to 4 words, cut at commas and pauses | TikTok, Reels and Shorts, burned into the video |
| Full subtitle lines | Up to 2 lines of 42 characters, a sentence at a time | YouTube videos, courses and interviews, as a subtitle file |
Short videos are watched on a phone, often with the sound off, so their captions are big, a few words at a time, and on the picture. For more on styling them, read how to caption short videos; for the files themselves, what an SRT file is.
How accurate auto captions are
The captions come from Whisper, OpenAI's speech recognition model, in a version small enough to run in a browser. Clear speech with little background noise comes out close to word for word. Names, brands, numbers and people talking over each other are where it slips, so read the captions through before you post: each line can be fixed in place. Convert an SRT to VTT, or shift its timing, with the SRT to VTT converter. The same speech model powers the bleep censor, which finds the swear words and bleeps them before you caption the clip.
Questions
How do I add captions to a video automatically?
Choose the video, pick the language (or let it detect it) and press Generate captions. Read them through, fix any word, then download an SRT or VTT file, or press Burn them into a vertical video to put them on the picture.
Is my video uploaded anywhere?
No. The captions are made by a speech recognition model (OpenAI's Whisper) running in your browser. The model is downloaded once, about 76 MB, and kept in your browser; your video never leaves your device.
Which languages does it understand?
About 100, the languages Whisper was trained on. It can detect the language for you, but picking it is more reliable for short clips or when people switch languages. English, Spanish, Portuguese, French and German come out best.
Can I edit the captions?
Yes. Every line can be changed before you download it, and its timing stays where it was. Names, brands and numbers are worth a check.
How long a video can it caption?
Up to 30 minutes at a time, from a video of any length: pick the part. On a computer's processor it takes about half as long as the part plays, and much less where the browser can use the graphics card.
How do I put the captions on TikTok, Reels or YouTube?
For short videos, burn them into the picture, so they look the same everywhere and can't be turned off. For a YouTube video, you can also upload the SRT file in YouTube Studio's Subtitles section, as a track viewers can turn on.
Captions on every clip, automatically
Paste a YouTube link and Clyper finds the best moments, frames them vertically and captions every word in the style you pick: up to 30 clips per video.
Guides
- Making clipsHow to add subtitles to a video (free)How to make subtitles automatically or by hand, fix them, and add them to YouTube, TikTok, Reels or an editor, as a file or burned in.7 min read
- GrowingHow to post a video on LinkedIn: specs, captions and vertical videoThe steps on desktop and mobile, LinkedIn's video specs, vertical video and the video tab, captions and thumbnails, and what to clip from long recordings.13 min read
- Making clipsHow to make sermon clips for YouTube Shorts, TikTok and ReelsFind the clips in Sunday's message, frame and caption them, and post them all week, with a workflow a volunteer team can keep.11 min read
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