How Image Cropper works
Choose a picture and a shape, and this tool cuts the largest region of that shape from the centre of the image. The presets are square (1:1), 4:3, 16:9, 3:4 portrait and 9:16 portrait. A 4032 x 3024 phone photo cropped to 1:1 becomes 3024 x 3024, with 504 pixels removed from each side. For anything else, choose Custom region below and enter a left offset, top offset, width and height in pixels. The crop is saved as a lossless PNG, and the work is done in your browser. There is no drag-to-select box: crops are set by preset or by numbers.
Crop sizes for common photo dimensions at each ratio
The largest centred crop for each preset, in pixels, worked out with the rule the tool uses. Whole means the picture already has that shape and nothing is removed.
| Original | 1:1 | 4:3 | 16:9 | 3:4 | 9:16 |
|---|---|---|---|---|---|
| 4032 x 3024 (phone, landscape) | 3024 x 3024 | Whole | 4032 x 2268 | 2268 x 3024 | 1701 x 3024 |
| 3024 x 4032 (phone, upright) | 3024 x 3024 | 3024 x 2268 | 3024 x 1701 | Whole | 2268 x 4032 |
| 4000 x 3000 | 3000 x 3000 | Whole | 4000 x 2250 | 2250 x 3000 | 1688 x 3000 |
| 6000 x 4000 (3:2 camera) | 4000 x 4000 | 5333 x 4000 | 6000 x 3375 | 3000 x 4000 | 2250 x 4000 |
| 1920 x 1080 (Full HD) | 1080 x 1080 | 1440 x 1080 | Whole | 810 x 1080 | 608 x 1080 |
| 1080 x 1920 (vertical video) | 1080 x 1080 | 1080 x 810 | 1080 x 608 | 1080 x 1440 | Whole |
| 2048 x 1536 | 1536 x 1536 | Whole | 2048 x 1152 | 1152 x 1536 | 864 x 1536 |
Where the exact result has a fraction, the saved file is rounded to the nearest whole pixel: 1687.5 becomes 1688 and 607.5 becomes 608.
How the centred crop is calculated
target = ratio width / ratio height. If image width / image height is greater than target: crop height = image height, crop width = image height x target. Otherwise: crop width = image width, crop height = image width / target. Left offset = (image width - crop width) / 2. Top offset = (image height - crop height) / 2.
The picture's own shape is compared with the target shape. If the picture is wider than the target, its full height is kept and the sides are trimmed; if it is taller, the full width is kept and the top and bottom are trimmed. Either way the same amount comes off both ends. For a 6000 x 4000 photo and 16:9, the target is 1.778 and the photo is 1.5, so the width stays at 6000 and the height becomes 6000 / 1.778 = 3375, starting 312.5 pixels from the top. The Crop region line shows rounded figures, so it reads 0, 313 with a size of 6000x3375.
Custom region examples: offsets, width and height
Coordinates start at 0, 0 in the top-left corner. The left offset moves the region right and the top offset moves it down.
Square crop pushed to the left edge
Image 4032 x 3024. Custom region: Left 0, Top 0, Width 3024, Height 3024
A 3024 x 3024 PNG of the left part of the photo. The centred preset would have started at 504 instead of 0.
For a 1:1 crop of this photo, any left offset from 0 to 1008 is valid.
Trimming a 40 px border from every side
Image 1920 x 1080. Custom region: Left 40, Top 40, Width 1840, Height 1000
A 1840 x 1000 PNG. Width is 1920 minus 80 and height is 1080 minus 80.
4:5 portrait, which is not a preset
Image 3024 x 4032. Custom region: Left 0, Top 126, Width 3024, Height 3780
A 3024 x 3780 PNG. 3024 x 5 / 4 = 3780, and (4032 - 3780) / 2 = 126 centres it vertically.
A region that does not fit
Image 1920 x 1080. Custom region: Left 1600, Top 0, Width 400, Height 400
No file. 1600 + 400 = 2000, which is past the 1920 pixel width, so the message says the crop region falls outside the 1920 x 1080px image.
Reduce the left offset to 1520 or the width to 320.
Limits worth knowing before you crop
Preset crops are always centred. The tool does not detect faces or subjects, so a person standing at the edge of a wide photo can be cut by a square crop. When that happens, switch to Custom region below, keep the same crop size from the table above and move the offset toward the subject.
There is no on-image selection box to drag. If you do not know the coordinates of the area you want, work them out from the picture's dimensions, which appear as Original size after the first run, or use the Aspect Ratio & Crop Calculator on this site to get the crop size and centred offsets for other ratios such as 4:5, 3:2 and 21:9.
The custom fields start at 0, 0 and 400 x 400, so selecting Custom region below without changing them gives a 400 pixel square from the top-left corner. A picture smaller than 400 pixels on either side triggers the outside-the-image message until you lower the numbers.
Output is always PNG. That keeps the kept pixels exactly as they were, but a cropped camera photo saved as PNG can be a larger file than the JPEG you started with. Run the result through the Image Compressor or Image Converter if you need a small JPEG or WebP.
How to use it
- 1
Under Image, choose the photo. Files up to 30 MB are accepted.
- 2
Set Crop to: Square (1:1), 4:3, 16:9 widescreen, 3:4 portrait, 9:16 portrait or Custom region below.
- 3
For a custom crop, fill in Left offset (px), Top offset (px), Width (px) and Height (px). These four fields are ignored by the presets.
- 4
Read Original size and Crop region in the Details panel to confirm what was kept.
- 5
Download the result, saved as the original name with -cropped added and a .png extension.