What does resizing an image actually change?
Resizing changes the pixel dimensions of an image: its width and height in pixels. That is different from compressing, which keeps the dimensions and reduces file size by simplifying data. Making an image smaller in pixels generally makes the file smaller too, because there is simply less information to store.
Shrinking an image is safe and common. Enlarging is different: the tool can stretch pixels to a larger size, but it cannot invent real detail, so enlarged images tend to look soft or blocky.
When you need to resize an image
Resizing comes up constantly: a profile photo that must be a certain size, a banner for a website section, a product image that needs consistent dimensions, or a photo that is far larger than it needs to be for a page or an email.
Phone and camera photos often contain millions of pixels, much more than a web page displays. Scaling them down before uploading saves bandwidth and storage and loads faster for visitors.
If you only want to cut out part of the picture rather than scale the whole thing, use crop image. If size in kilobytes is the concern rather than pixels, try the image compressor.
How to resize an image with this tool
- Drop an image onto the upload area or click to choose one. The original name, file size and pixel dimensions are displayed.
- The Width (px) and Height (px) fields are filled with the current dimensions.
- Type a new width or height. With Lock aspect ratio ticked (the default), the other value updates automatically to keep proportions.
- Untick the box if you want to set both numbers independently.
- Click Resize, check the preview and the size change, then click Download.
The file is saved as your original name plus "-resize", using the same image type as the source. Everything runs in your browser, so nothing is uploaded.
Tips and limits
Keep the aspect ratio locked unless you really want to stretch or squash the picture. Typing mismatched width and height with the lock off will distort the image.
There are no preset sizes here. You enter exact pixel values yourself, so know your target dimensions before you start.
Output type follows the input. A JPG stays a JPG and a PNG stays a PNG. If you want a different format afterwards, run the result through a converter such as PNG to JPG.
Resize from the original. Scaling a picture down and later back up costs quality, so keep your full-size file.
Large images use more of your device's memory while processing, which matters mainly on older phones.