Crop an Image
Pick an image, set the crop rectangle — it's cropped in your browser, nothing is uploaded.
Crop an image in your browser
Pick an image, set the top-left corner (X and Y) and the width and height of the rectangle you want to keep, and get the cropped copy instantly. The cropping runs entirely in your browser with ffmpeg compiled to WebAssembly — your image is never uploaded to a server.
How the rectangle works
The origin (0, 0) is the top-left corner of the image.
- X offset — how far from the left edge the crop starts, in pixels.
- Y offset — how far from the top edge the crop starts, in pixels.
- Width — how wide the kept rectangle is, in pixels.
- Height — how tall the kept rectangle is, in pixels.
Tips
- Keep the rectangle inside the image's dimensions, or ffmpeg will reject it.
- Works offline once the page has loaded.
FAQ
Which image formats can I crop?
The common web formats — PNG, JPEG, WebP, BMP, GIF — anything the bundled
ffmpeg build can decode. The cropped copy keeps the same format as the
original: crop a .jpg and you download a .jpg, crop a .png and you get
a .png.
What if my crop rectangle sticks out past the edge?
The crop fails: ffmpeg rejects a rectangle that isn't fully inside the image
rather than silently clamping it. Make sure X + width stays within the image
width and Y + height within the height. Width and height must both be at
least 1 pixel.
Does cropping reduce image quality?
The pixels you keep are copied 1:1 — no scaling happens — but the file is re-encoded on save. For lossless formats like PNG that's a perfect copy; for JPEG the re-encode introduces one generation of compression, as any JPEG editor does.
Is my photo uploaded to a server?
No. The crop runs in your browser with ffmpeg compiled to WebAssembly, so the image never leaves your device — it even works offline once the page has loaded.
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool image-crop 'url=https://example.com/input' 'x=0' 'y=0' 'width=640' 'height=480'New to the CLI? Get gizza →
Open it by URL
Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:
https://gizza.ai/tools/image-crop/?url=https://example.com/input&x=0&y=0&width=640&height=480Machine-readable descriptor: tool.json — title + parameters JSON Schema for agents.