Which aspect-ratio presets are available?

You can crop to 1:1 (square — Instagram feed), 16:9 (widescreen — YouTube, TVs), 4:3 (classic monitors and SD video), 9:16 (vertical — TikTok, Reels, Shorts), or define a free rectangle with manual pixel coordinates.

How do I pick the crop region?

Choose an aspect-ratio preset, then fine-tune the X, Y offset and the output width and height in pixels. The tool calculates a default centered crop matching the preset, which you can adjust before encoding.

Does cropping change the video resolution?

Yes — cropping removes pixels at the edges, so the output is smaller than the source. There is no upscaling involved; the kept area is preserved at its original pixel density.

Will cropping reduce the file size?

Usually, yes. A smaller frame contains fewer pixels per second and compresses to a smaller file at the same quality preset. Cropping a 4K video down to 1080p square format typically cuts file size by 60% or more.

Is the audio track preserved?

Yes. Cropping only affects the visual frame; the audio track is stream-copied without re-encoding, so there is no audio quality loss and the audio export is near-instant.

Is my video uploaded anywhere?

No. ffmpeg.wasm runs entirely inside your browser via WebAssembly. The file never leaves your device, making this safe for sensitive personal or business footage.

Video Cropper

Crop any video to a square, vertical, widescreen, or custom rectangle — entirely in your browser, no upload.

100% client-side · no upload

Video file (MP4, WebM, MOV…)

Load a video file to begin.

How to crop a video

Select your video file — MP4, WebM, MOV, MKV all work.
Pick an aspect-ratio preset, or choose Free to enter custom dimensions.
Adjust the X / Y offset and width / height in pixels to frame the area you want to keep.
Click Apply crop and download the result.

Common use cases

Vertical reels: Crop a landscape recording to 9:16 for TikTok, Instagram Reels, or YouTube Shorts.
Square thumbnail: Centre-crop a horizontal video to 1:1 for Instagram feed posts and Facebook ads.
Hide watermarks or bars: Trim off black bars at the edges, a corner watermark, or a recording-software toolbar.
Re-frame action: Move the focal subject into the centre by shifting the crop rectangle.

Related tools: Video Resizer · Change Aspect Ratio · Video Rotator · Video Trimmer

よくある質問

Which aspect-ratio presets are available?: You can crop to 1:1 (square — Instagram feed), 16:9 (widescreen — YouTube, TVs), 4:3 (classic monitors and SD video), 9:16 (vertical — TikTok, Reels, Shorts), or define a free rectangle with manual pixel coordinates.
How do I pick the crop region?: Choose an aspect-ratio preset, then fine-tune the X, Y offset and the output width and height in pixels. The tool calculates a default centered crop matching the preset, which you can adjust before encoding.
Does cropping change the video resolution?: Yes — cropping removes pixels at the edges, so the output is smaller than the source. There is no upscaling involved; the kept area is preserved at its original pixel density.
Will cropping reduce the file size?: Usually, yes. A smaller frame contains fewer pixels per second and compresses to a smaller file at the same quality preset. Cropping a 4K video down to 1080p square format typically cuts file size by 60% or more.
Is the audio track preserved?: Yes. Cropping only affects the visual frame; the audio track is stream-copied without re-encoding, so there is no audio quality loss and the audio export is near-instant.
Is my video uploaded anywhere?: No. ffmpeg.wasm runs entirely inside your browser via WebAssembly. The file never leaves your device, making this safe for sensitive personal or business footage.

このツールの問題を報告