About the Image Cropper
This image cropper lets you trim a photo, screenshot or graphic right in your browser. Upload an image, drag the crop box or its corners, or pick a preset aspect ratio — square for Instagram posts, 4:5 for portrait feeds, 16:9 for YouTube thumbnails, 9:16 for Stories and Reels, 3:2 or 5:4 for prints — and download the result as PNG, JPG or WebP. You can also type exact pixel coordinates for a precise crop.
It is handy for social-media managers resizing a shot for several platforms, photographers preparing prints at a fixed ratio, sellers squaring up product photos, and anyone who needs a quick crop without installing software. Your image never leaves your device: it is read and cropped locally with the browser’s canvas, so it works for private photos too.
The calculator section below shows the maths behind ratio presets: for any image size and aspect ratio it finds the largest centred crop, its pixel dimensions, the offsets from the top-left corner and how much of the original image is kept.
How to use the image cropper
- 1Upload or drop an image into the cropper — it stays on your device.
- 2Pick an aspect-ratio preset, or choose Free to crop any shape.
- 3Drag the box to position it and pull a corner to resize it.
- 4Fine-tune with the X, Y, width and height fields if you need exact pixels.
- 5Choose PNG, JPG or WebP and download the cropped image.
Formula and method
An aspect ratio r is the crop’s width divided by its height (16:9 = 1.778). If the image is relatively wider than the target ratio, the crop keeps the full height and trims the sides to H × r pixels; otherwise it keeps the full width and trims the top and bottom to W ÷ r pixels. The result is rounded to whole pixels, so the crop is the largest possible at that ratio.
Centring the crop means splitting the removed pixels equally between both sides, so the left (or top) offset is half the difference, rounded down. In the interactive cropper you can drag the box anywhere; the dimensions stay locked to the ratio while you resize from the corners. The area kept is the crop’s pixel count divided by the original’s.
- W, H
- Original image width and height (px)
- r
- Target aspect ratio, width ÷ height
Worked examples
24 MP photo (6000 × 4000) cropped to 16:9
A 3:2 photo (ratio 1.5) is narrower than 16:9 (1.778), so the full 6,000 px width is kept and the height becomes 6000 ÷ 1.778 = 3,375 px. The 625 px removed are split top and bottom, starting 312 px from the top, and 84.4% of the picture remains.
Phone photo (4032 × 3024) cropped square
A 4:3 phone image is wider than square, so the full 3,024 px height is kept and the width is trimmed to 3,024 px, starting (4032 − 3024) ÷ 2 = 504 px from the left. The square keeps 75% of the image, about 9.1 MP.
1920 × 1080 screenshot cropped to 4:5 for an Instagram portrait post
A 16:9 frame is far wider than 4:5 (0.8), so the full 1,080 px height stays and the width becomes 1080 × 0.8 = 864 px, starting 528 px from the left. Only 45% of the screenshot survives, so frame your subject in the middle.
Frequently asked questions
Is it safe to crop private photos here?+
Yes. The image is loaded into your browser and cropped with the HTML canvas on your own device. Nothing is uploaded to a server, and the file disappears when you close the page.
What aspect ratio should I use for Instagram?+
Use 1:1 for square posts, 4:5 for portrait feed posts and 9:16 for Stories and Reels. Landscape posts can go as wide as 1.91:1. Instagram changes its layouts from time to time, so check the current guidance if a crop looks wrong after upload.
Does cropping reduce image quality?+
Cropping removes pixels but does not blur the rest. Downloading as PNG is lossless; JPG and WebP re-compress the image, so keep the quality high if you will edit it again. A heavy crop leaves fewer pixels for printing large.
Why is my downloaded file larger or smaller than the original?+
The crop is re-encoded by your browser, which may use different compression than your camera. PNG files are usually much larger than JPGs for photos, while WebP is typically the smallest at similar quality.
Does cropping keep the photo’s EXIF data?+
No. Re-encoding through the canvas drops EXIF metadata, including camera settings and GPS location. That is good for privacy; use an EXIF viewer first if you need to record the details.