YouTube Shorts editor online, vertical, no upload

Repurpose long-form clips into Shorts without a cloud timeline. Supercut reframes and captions locally so your source masters stay private.

Open the editor, freeNo upload · No sign-up to start · 100% private

Just type

Crop for YouTube Shorts and add captions

Works with

MP4MOVWebM

How it works

  1. 1

    Drop your clip

    Load the source video in the editor, nothing uploads.

  2. 2

    Ask for Shorts format

    Say “Shorts vertical with captions” or trim to under 60 seconds first.

  3. 3

    Export Shorts-ready

    Download a vertical captioned file and upload to YouTube from your device.

Tips

  • Shorts are 9:16 and usually under 60 seconds.
  • Lead with the payoff to hold the first seconds.
  • Repurpose long-form by trimming the best moment.

Why it stays private

Supercut decodes, edits and exports your video entirely in your browser with WebAssembly. Your footage is never uploaded, the only thing that leaves your device is the text of your prompt, so the AI knows what edit to plan. Read more in our Privacy Policy.

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Who uses this

Frequently asked questions

What specs do Shorts need?

9:16 vertical, ideally 1080×1920, typically under 60 seconds for Shorts feed placement.

Can I trim to 60 seconds?

Yes. Ask to trim to the hook you want, then reframe to vertical.

Is processing in the cloud?

No. Shorts prep runs entirely in your browser.

Ready to try it?

Drop a clip and describe the edit, it runs right here in your browser.

Open the editor