Video Cropper 9:16

Convert horizontal video to vertical — for free, in your browser

Tools like OpusClip and Munch charge $20-50 / month to take a horizontal video and reframe it to 9:16 for TikTok, Reels and YouTube Shorts. They process on their servers and limit the number of clips you can make per month. This page does the same job 100% in your browser, with no subscription, no upload, no watermark and no monthly cap.

How it works

We use WebCodecs, the modern browser API that exposes hardware-accelerated video encoding directly to JavaScript. When you click Export:

1. The original video is decoded by your browser (whatever codec it supports).
2. Each frame is drawn to an offscreen canvas at the target aspect ratio, with the chosen crop region.
3. The frames are re-encoded with VideoEncoder — to H.264 for MP4 output or VP9 for WebM.
4. Audio is decoded with Web Audio API and re-encoded with AudioEncoder (AAC for MP4, Opus for WebM).
5. Everything is packaged into a downloadable file using a small WASM-free muxer library.

Aspect ratios for every platform

• 9:16 — TikTok, Instagram Reels, YouTube Shorts, Facebook Stories, Snapchat.
• 1:1 — Instagram feed (square posts), Twitter/X.
• 4:5 — Instagram feed (portrait posts) — takes more vertical screen space than 1:1.
• 16:9 — YouTube long-form, X video posts. Useful for re-formatting a vertical clip back to horizontal.

Trim and reposition

After loading a video, drag the two indigo handles on the timeline to set the start and end of your clip. Drag inside the video preview to reposition the crop rectangle — handy if the action isn't in the center of the frame. Choose "Left", "Right", "Top" or "Bottom" alignment as a starting point.

MP4 vs WebM — which to pick?

MP4 (H.264) works literally everywhere — every social platform, every device, every editing tool. WebM (VP9) produces smaller files at the same quality but TikTok, Instagram and most editing tools will reject or transcode it. Use MP4 unless you specifically need WebM.

Privacy

Your video never leaves your device. All decoding, cropping and encoding happens in your browser tab using your CPU and GPU. We don't have a server-side component for this tool. The browser tab can be closed at any time and nothing remains.

Browser support

WebCodecs is supported in Chrome 94+, Edge 94+ and Safari 16.4+. Firefox: WebCodecs support has been catching up — check version 130+. We feature-detect and show a clear notice if your browser can't handle it.

Limits

• Length: under 2 minutes works best — longer clips take time and memory.
• Resolution: anything up to 4K decodes fine; output is capped at 1080p to keep encoding fast.
• Codecs: input must be playable by your browser (MP4, MOV, WebM standard codecs all work).

Common use cases

• Repurpose a horizontal YouTube clip as a TikTok / Reel without paying OpusClip.
• Crop a podcast clip vertically for Instagram Stories.
• Trim a long screen recording down to just the interesting 30 seconds.
• Convert a square Instagram post to portrait 4:5 for better feed visibility.
• Resize a webinar recording from 16:9 to 1:1 for X (Twitter) posts.