How to use the video cropper
- Drop a video onto the box or click to choose one.
- Choose a Shape: 1:1 square (default), 16:9 landscape, 9:16 vertical, 4:3, 4:5 portrait, 21:9 cinema, or Free (enter a rectangle).
- For a set shape, choose what to Keep: Centre, Left / top or Right / bottom.
- For Free, enter Left edge, Top edge, Width and Height as percentages of the frame. The starting values (10, 10, 80, 80) trim a 10% border from every side.
- Pick an Output format and press Crop video. Check the result in the player, then download it.
What it does and when to use it
Cropping removes parts of the picture you do not want: a messy edge of the room, a taskbar in a screen recording, black letterbox bars, or the space around a subject when you need a square or vertical clip. The cropper always takes the largest area of your chosen shape that fits inside the frame, then slides it to the side you asked to keep.
When you are preparing a clip for a specific social platform, the social media video cropper also scales to the usual upload size and can add bars instead of cutting. If the clip is sideways, fix it with the video rotator first. To change the size without losing any of the picture, use the video resizer.
How it works
The tool reads the video’s display size, works out the crop rectangle, and then decodes, crops and re-encodes every frame with Mediabunny and the browser’s WebCodecs encoder in a background worker. Cropping always re-encodes, because the stored frames cannot be cut without decoding them. The file never leaves your device.
For a set shape, the crop is as wide as the frame allows unless that makes it too tall, in which case it is as tall as the frame allows. Keep decides where the leftover space goes: all on one side, all on the other, or split evenly.
Worked examples
These rectangles come from the tool’s own crop maths.
| Source | Settings | Result |
|---|---|---|
| 1920×1080 | 1:1, Centre | 1080×1080 at (420, 0) |
| 1920×1080 | 9:16, Left / top | 608×1080 at (0, 0) |
| 1920×1080 | 21:9, Centre | 1920×822 at (0, 129) |
| 1920×1080 | Free, 10 / 10 / 80 / 80 | 1536×864 at (192, 108) |
| 1080×1920 (portrait) | 4:5, Centre | 1080×1350 at (0, 285) |
Limits and tips
- Re-encoding takes time and loses a little quality. Keep the original file and crop from it, not from an earlier crop.
- 4K and long clips need plenty of memory, because the result is built in the tab. Phones may be slow; use Cancel if needed.
- AVI, WMV, FLV and MPG cannot be read here. Convert them first with the video converter.
- If MP4 output fails in your browser, choose WebM in Output format.
Frequently asked questions
How do I remove black bars from a video?
Does cropping make the video smaller in pixels?
Can I see the crop before exporting?
Why are my numbers changed slightly?
Is the sound kept?
How do we know nothing is uploaded? Test it yourself on the privacy proof page.