How to crop a video
- Add your video. Drop an MP4, MOV, WebM, MKV or AVI file. The bar under the preview shows its resolution, duration, size and format.
- Trim. Drag the two handles on the timeline, or focus a handle and use the arrow keys, to keep only the part you need.
- Choose the shape. Pick a ratio preset, or Custom to drag and resize a crop box over the picture.
- Rotate, flip or mute if needed, choose MP4 or WebM and a quality level, then press Export Cropped Video.
- Check and download. The result plays on the page before you save it.
Which aspect ratio for each platform?
| Ratio | Shape | Typical use |
|---|---|---|
| 9:16 | Vertical full screen | TikTok, Instagram Reels and Stories, YouTube Shorts |
| 4:5 | Tall portrait | Instagram and Facebook feed posts |
| 1:1 | Square | Feed posts, profile videos, carousels |
| 16:9 | Widescreen | YouTube, presentations, TVs and monitors |
| 21:9 | Ultrawide | Cinematic banners and trailers |
| 2:3 | Portrait | Pinterest pins |
Platforms change their recommendations from time to time, so check the upload screen of the app you are posting to.
Centre presets versus custom crop
Presets keep the largest possible area of the chosen shape and cut equally from both sides, which works when the subject is in the middle. Turning a 16:9 landscape clip into 9:16 keeps only about a third of the width, so a person standing to one side may be cut off; use Custom and drag the box over them instead. The custom box is measured against the real picture, including any black bars around it, and the crop is applied before rotation.
Rotate, flip and audio
Rotation turns the picture in 90° steps, which fixes clips recorded sideways. Horizontal flip mirrors selfie footage. Keep Audio re-encodes the sound; switch it to muted to drop the soundtrack entirely.
MP4 or WebM, and quality
MP4 uses H.264 video and AAC audio and is the right choice for almost every app. WebM (VP8 and Vorbis) suits some websites but encodes several times slower in the browser. Low, Medium and High set the quality for MP4 at CRF 35, 28 and 18; High keeps the most detail and makes the largest file. To shrink the result further afterwards, use the Video Compressor.
How your file is handled
The FFmpeg engine and the slider library are loaded from public content networks, and the video is cropped inside your browser tab. It is not uploaded to FastSaveMedia.