Resize image dimensions online
Pick a photo, type the width or height you need, and resize image files to exact pixel dimensions, saved as a sharp PNG.
Last updated
Your files never leave your device. Everything is processed in your browser and nothing is uploaded.
How to resize image files
- Press Choose image, or drop a JPG, PNG or WebP file onto the box. Its current size in pixels is shown.
- Type a new width. With the aspect ratio locked, the height updates automatically, and the other way round.
- Press the chain button if you need to set both sides freely; the picture may then stretch.
- Press Resize image, then Download PNG.
How the image resizer works
The resizer draws your image onto a canvas of the new size in your browser, using the highest-quality smoothing the browser offers, and saves the result as a PNG. PNG is lossless, so the change of size is the only change: no compression artefacts are added on top.
Locking the aspect ratio keeps the picture's proportions, so faces and circles don't get squashed or stretched. Your image never leaves your device.
Formula
With the ratio locked: new height = new width × original height ÷ original width, rounded to the nearest whole pixel. Changing the height works the same way in reverse.
Each side can be anything from 1 to 10,000 pixels.
Example
A 4,032 by 3,024 phone photo resized to a width of 1,200 pixels gets a height of 1,200 × 3,024 ÷ 4,032 = 900 pixels. The new image has about 1.1 million pixels instead of 12.2 million, so it loads far faster on a web page.
Profile pictures often need a square. Unlock the ratio and enter 400 by 400 only if the photo is already close to square; otherwise crop it first so it doesn't look stretched.
Tips and common mistakes
Shrink, don't enlarge
Making a small image bigger can't add detail that isn't there; it just looks soft. Always start from the largest original you have.
Resize first, then compress
Lossless PNG files can be large. For photos on a website, resize first and then compress the image to a smaller JPG.
Use WebP for websites
After resizing, convert the image to WebP for an even smaller file that all modern browsers can show.
Match the size a site asks for
Forms, shops and social networks often list exact pixel sizes. Matching them avoids automatic cropping that can cut off part of your picture.
Keep the original safe
The download is named with its new size, such as photo-1200x900.png, so the original file on your device stays untouched.
Frequently asked questions
Are my images uploaded?
No. Resizing happens in your browser and the image never leaves your device.
Why is the result a PNG?
PNG is lossless, so the resized image keeps all the detail its new size allows. Convert it to JPG or WebP afterwards if you need a smaller file.
Will resizing reduce the file size?
Fewer pixels usually means a much smaller file. Because PNG is lossless, though, a resized photo can still be bigger than the original JPG; compress it to fix that.
Can I resize several images at once?
Not at the moment. The resizer handles one image at a time so you can check each result.
What is the largest size allowed?
Up to 10,000 pixels on each side. Larger canvases fail on many phones and tablets.