How to crop a photo to an exact ratio or pixel size (4:5, 1:1, 1080×1350…)

Updated 2026-11-05

"Make it 4:5" or "it has to be 1200×630" sounds simple, yet it is easy to end up with a squashed picture or a crop that refuses to change shape. The trick is to treat shape (ratio) and size (pixels) as two separate steps.

Ratio first, pixels second

The ratio is the shape of the picture: 1:1 is square, 4:5 is slightly tall, 16:9 is wide. Pixel size is how big that shape is: 1080×1350 and 2160×2700 are both 4:5. Crop to get the right shape, then resize to get the right number of pixels. Doing it the other way round either stretches the image or forces the app to crop for you.

Why the crop box keeps its old shape

Many editors start the crop tool in "Original" mode, which locks the box to the photo's current ratio. Dragging a corner then only makes the box smaller at the same shape, which feels like the crop is broken.

In the Localvert photo editor the crop tool opens in Custom mode, so the box can take any shape: drag a corner or the middle of a side. To lock a specific shape, open the crop menu under the photo and pick a ratio — square 1:1, 4:5, 3:4, 4:3, 3:2, 2:3, 16:9 or 9:16 — then move the box to choose what to keep.

Getting an exact pixel size

For social media, open Social media in the crop menu and pick the format, such as Instagram portrait post (1080×1350), story or Reels (1080×1920), YouTube thumbnail (1280×720) or X post (1600×900). The box locks to that shape and the saved image is exactly that many pixels — no separate resize needed.

For any other size, crop to the matching ratio first (1200×630 is about 1.9:1, so use Custom and watch the size readout), then open the Resize tab and type the width. With the lock icon closed, the height follows automatically and nothing gets distorted.

When the resize lock is open

The lock icon between the width and height fields keeps the proportions. If you open it and type both numbers, the picture is stretched or squashed to fit — faces get wider, circles turn into ovals. Leave it locked unless you really want to distort the image, and change the shape with the crop tool instead.

Quality and saving

Cropping removes pixels, so a tight crop of a small photo can end up below the size you need. Avoid making an image larger than it really is — enlarging a 600-pixel crop to 1080 pixels adds blur, not detail.

Save photos as JPG, graphics with text or transparency as PNG, and images for websites as WebP. The editor works entirely in your browser, and the original file on your device is never changed: you always save a new copy.