Image Resizer: how to use it
A practical guide to resizing photos to exact pixel dimensions in your browser, including aspect ratio, enlarging and the right size for web and forms.
Resizing changes how many pixels an image contains. Social media, job portals, e-commerce listings and exam forms often ask for an exact width and height, and a photo straight from a phone camera is almost never the right size. The Image Resizer sets the dimensions you type and gives you a new file, without uploading the original anywhere.
Unlike compression, resizing really removes pixels, so it cannot be undone. Always keep the original file and save the resized copy under a new name.
How to use the Image Resizer
- Select an image. The width and height boxes fill in automatically with the picture's current size.
- Type the new width or height in pixels. While Keep original aspect ratio is ticked, the other value updates to match so the picture is not stretched.
- Untick Keep original aspect ratio only if you need an exact width and height that do not match the original proportions. The picture will be stretched or squashed to fit.
- Press Process image and check the preview.
- Press Download result. PNG and WebP inputs keep their format; other images are saved as JPEG.
Tips for better results
- Making an image smaller is safe. Making it larger only spreads the same pixels over more space, so it looks soft. Avoid enlarging beyond about 150%.
- For a web page, a width of 1200 to 1600 pixels covers almost every screen. Mobile-only images rarely need more than 800.
- If a form wants an exact ratio such as 4:5, crop first with the Image Cropper and then resize, which avoids distortion.
- Resize first, then compress. Doing it in that order gives the smallest file for a given quality.
Pixels, not centimetres
A pixel count has no physical size until you assign a resolution. If a form asks for a size in millimetres or inches, use the Photo Dimensions Converter to turn it into pixels at 300 DPI, then enter those pixels here.
Frequently asked questions
Why does the height change when I type a width?
That is the aspect-ratio lock doing its job. Untick it to set both values independently.
Can I resize several images at once?
The tool handles one image at a time, which keeps everything fast and private. Repeat the steps for each file.
What happens to a transparent PNG?
PNG and WebP keep their transparency. A JPEG has no transparency, so any transparent area would become solid.
Related guides and tools
Image Compressor
Learn how to reduce the file size of JPG, PNG and WebP photos in your browser without uploading them, and how to choose the right quality setting.
Read the guide · Open the toolImage Cropper
How to crop an image to exact pixel coordinates in your browser, with a simple method for choosing X, Y, width and height.
Read the guide · Open the toolPhoto Dimensions Converter
Convert photo sizes between pixels, millimetres, centimetres and inches at any DPI.
Read the guide · Open the tool