TikTok, Reels, and Shorts all want a tall 9:16 frame, but most footage is shot wide in 16:9. Making it vertical means cropping or reframing so your subject fills a portrait screen instead of sitting in a small letterboxed strip. In Supercut you do this by typing a plain-English prompt, and the whole job runs in your browser, so your footage is never uploaded.
Vertical video means a 9:16 aspect ratio: nine units wide for every sixteen units tall. That is the full-screen shape for TikTok, Instagram Reels, and YouTube Shorts, and 1080x1920 is the common upload size. By contrast, 16:9 is the wide format from most cameras and screen recordings, and 1:1 is the square middle ground that suits older feed posts. Drop a 16:9 clip straight into a vertical feed and the platform usually pads it with black or blurred bars, so the actual picture sits in a thin band in the middle. Converting to true 9:16 fills the screen instead.
There are two honest ways to go vertical. A straight crop keeps a fixed tall slice of the frame, which is fast and works when your subject stays put, for example a centered talking head. Smart reframe is better when the subject moves: it tracks faces on your device and pans the 9:16 window to follow them, so a person walking across a wide shot stays inside the vertical cut. Supercut supports both. Use a plain crop for static shots, and smart reframe for anything with movement or a subject who drifts away from center.
Supercut runs FFmpeg in your browser through WebAssembly, so decoding, cropping, reframing, and exporting all happen on your own device. Your video file never leaves your computer. Only the short text prompt you type is sent, so the AI can plan the edit. That means you can reframe sensitive or unreleased footage without handing it to a server, and once the page has loaded you can keep working even if your connection drops.
Open the Supercut editor and drag your video in. It loads straight into the page on your device. No upload, and no account is needed to try your first export.
Say what you want, for example "crop this to 9:16 vertical for TikTok" or "smart reframe to 9:16 and keep my face centered." The AI plans the edit and a deterministic engine maps it to the exact FFmpeg crop.
Look at the result and confirm your subject sits inside the tall 9:16 window with a little headroom. If the framing is off, refine your prompt, for example "shift the crop left" or "use smart reframe instead."
Useful for social: ask for auto-captions, generated on-device with Whisper, or apply a platform export preset for TikTok, Reels, or Shorts so the size matches where you are posting.
Export the finished 9:16 clip and save it to your device. The encode runs locally, so your footage is never sent anywhere, and you get a vertical file ready to post.
Crop and reframe any video to 9:16 for TikTok, Reels and Shorts. Subject-tracking keeps the action in frame, all in your browser, no upload.
Edit videos for TikTok in your browser. Auto 9:16 reframe, captions, and export, your footage never uploads to TikTok or anyone else first.
Add auto-captions to any video in your browser. On-device transcription with viral caption styles, no upload, your footage and audio stay private.
Reframe to 9:16, add viral captions, trim hooks, and export TikTok-ready clips in your browser. No upload before you post.
Reframe, caption, and batch-process client clips in your browser. No uploading client footage to a third party, and no watermark on paid exports.
Use 9:16 for TikTok, Instagram Reels, and YouTube Shorts, with 1080x1920 as the standard full-screen size. Square (1:1) and wide (16:9) are different shapes that will not fill a vertical feed.
Cropping to 9:16 keeps a tall slice of the original frame, so the kept area stays as sharp as the source; you are trimming the sides, not stretching pixels. Avoid scaling a small clip up past its native resolution, since that is where softness creeps in. Doing the edit in one pass in Supercut keeps quality loss minimal.
No. Supercut decodes, crops or reframes, and re-exports entirely in your browser via WebAssembly, so your footage never leaves your device. Only the text prompt you type is sent, so the AI can plan the edit.
Use smart reframe instead of a fixed crop. It tracks faces on your device and pans the 9:16 window to follow the subject, so someone moving across a wide frame stays inside the vertical cut. Just ask for "smart reframe to 9:16."
You can try your first export free with no account. Paid unlocks unlimited watermark-free exports and every tool, starting at 4.99 per month billed yearly (59.88 per year), 9.99 monthly, or 199 one-time lifetime. You can cancel anytime.