Crop an image
Drag a box over your photo to crop it, right in your browser. Works with the keyboard too, and the picture is never uploaded anywhere.
Drop a file here
or paste from the clipboard
Crop area
Choose an image and a crop box appears here.
Drag inside the box to move it, or a corner to resize. With the keyboard: Tab to the crop area, then arrows to move, Shift and arrows for ten pixels, Home to reset. Tab again to resize.
How it works
Your image is decoded once for the preview and drawn to a canvas sized to fit the stage. The rectangle you drag is stored as four fractions of the source image rather than as screen pixels, so nothing about your display's scaling can reach the result. The worker multiplies those fractions back up to whole pixels, clamps them to the image bounds, and copies just that region.
Measured results
These figures come from running this exact tool over a fixed set of sample files on every build, not from an estimate.
| Sample file | Settings | Before | After | Change |
|---|---|---|---|---|
| logo-transparent.png | centre half | 19 KB | 5 KB | −74% |
| photo-gradient.jpg | centre half | 504 KB | 117 KB | −77% |
| photo-gradient.png | centre half | 3.36 MB | 864 KB | −75% |
| screenshot-text.png | centre half | 219 KB | 58 KB | −74% |
- logo-transparent.png: from: 512x512 · to: 256x256 · before: 18.7 KB · after: 4.9 KB
- photo-gradient.jpg: from: 1600x1000 · to: 800x500 · before: 504.1 KB · after: 117.0 KB
- photo-gradient.png: from: 1600x1000 · to: 800x500 · before: 3.36 MB · after: 864.5 KB
- screenshot-text.png: from: 1280x800 · to: 640x400 · before: 219.0 KB · after: 58.0 KB
Benchmark run 2026-08-01.
What to watch out for
A single rectangle cannot mean the same thing on a 4000 by 3000 photograph and a 512 pixel logo, and the preview can only show one file. Allowing a batch would quietly cut different content out of each image, so the build refuses to let this tool accept more than one.
Decoding a fifty-megapixel photograph at full resolution needs around two hundred megabytes of memory on the main thread, which is enough to crash a browser tab on a phone. Above roughly twenty megabytes the preview is scaled down. The crop itself still runs at full resolution, so only the on-screen picture is coarser.
JPEG can in principle be cut losslessly along its eight-pixel block boundaries, but that path is not reachable through a canvas. The image is decoded and encoded again, so a little quality is spent. Choose PNG under "save as" if the result must not lose anything further.
Limits
Files up to about 50 MB work reliably. Beyond that, the ceiling is your device's memory rather than any rule we impose — the work happens on your own machine. Tested in Chrome 140, Firefox 143, Safari 18.
Dragging, and the alternative
Most privacy-respecting crop tools ask for four numbers: left, top, width, height. That is a fine data model and a miserable way to frame a photograph, because you cannot see what you are doing until you have already done it.
This one shows the picture and lets you drag a box across it. Grab the middle to move the selection, grab a corner to resize it, and the area outside dims so the result is obvious before you commit. The pixel figures update as you drag, for the times when an exact size matters more than the framing.
It works without a mouse
The crop area is reachable by keyboard, which is unusual for a control like this and not decorative.
Tab moves focus to the crop area; the arrow keys then nudge it one pixel at a time, Shift with an arrow moves ten, and Home resets to the whole image. Tab once more and focus lands on the bottom-right handle, where the same keys change the size instead of the position. Every change is announced, so the control is usable without seeing the screen at all.
Proportion locking
Free-form cropping is the default because most of the time you are simply cutting away what you do not want. When the result has to fit somewhere specific, the proportion lock keeps one ratio fixed while you resize: square for an avatar, four by five for a portrait post, sixteen by nine for a slide or a thumbnail.
“Same as the original” is the option people forget exists. It keeps the picture’s own shape while you cut into it, which is what you want when the crop is going back where the original came from.
Why the numbers are fractions
The rectangle you drag is recorded as a proportion of the image — a tenth from the left, four fifths wide — rather than as a number of pixels on your screen.
This sounds like an implementation detail and is actually the reason the tool is accurate. Screens differ in pixel density, and the preview is scaled to fit the panel, so a measurement taken in screen pixels would need two conversions before it meant anything. Fractions survive both. Whatever the preview happens to be showing, the crop applies to the full-resolution image exactly where you put it.
Nothing is uploaded
The preview, the drag and the cut all happen inside your browser. Cropping is something people do to screenshots of private conversations, to documents before sharing them and to photographs before posting them — precisely the images that should not be handed to a server first. The file on your disk is never modified either; you get a new one.
Your files never leave your browser. Last updated 2026-08-01.
Next step
Your file is already here in this browser, so the next tool starts with it loaded.
- Resize an imageChange an image's dimensions in your browser. Set a width, a height or both, keep the aspect ratio, and pick the output format. Nothing is uploaded.
- Compress a JPGShrink JPG photos in your browser with MozJPEG, the same encoder Mozilla built for the web. Typically 20 to 40 percent smaller than a plain re-save.