Turn a long video into vertical clips

How it works

1. 1

   Drop in your video

   An MP4, MOV or other video file, or a YouTube link. Up to 30 minutes.

2. 2

   We reframe and caption

   Each moment is cut to vertical, with captions that follow the speaker.

3. 3

   Post anywhere

   The same clip works on every short-video app. Download one at a time or all at once.

Everything you need to turn one video into many clips

Paste a link and Onyx finds the moments worth posting, cuts them to vertical, adds captions and tells you which ones should do best.

• Find a specific moment

  Tell the AI what you're after, like “the money advice” or “the funniest stories”, and it looks for those moments first.

• Virality score with a reason

  Every clip gets a score out of 100 and one plain sentence on why it should work, so you know what to post first.

• Captions that pop

  Captions timed to every word, in 5 styles: from bold with the spoken word lit up, to plain and quiet.

• Smart framing

  Face tracking follows the speaker. Split screen puts a facecam over the action, and Fit shows the whole picture on a blurred background.

• Remove pauses

  Long silences between words are cut down to a short breath, and the captions stay in sync.

• Paste a link or upload

  YouTube videos, finished live streams and your own video files, up to 30 minutes long.

• Clips as they finish

  Watch and download each clip the moment it's ready, while the rest are still being made.

• Private by default

  Only you can see your videos and clips, and the files delete automatically after 7 days.

More free tools

• YouTube to Shorts
• Podcast to clips
• See pricing