Image resizer
Change an image to exact pixel dimensions, or scale it down by percentage, with the aspect ratio held for you. Everything runs in your browser — no upload, no account, no watermark.
- Nothing uploaded
- No sign-in
- No watermark
Resize an image
How to use this tool
- Choose an image. The current dimensions appear under the file picker.
- Type the width or height you need — with Keep aspect ratio ticked, the other box follows automatically.
- Or switch to Percentage if you just want the image at half or a quarter of its current size.
- Pick an output format and select Resize image.
Why aspect ratio matters
Forcing an image into dimensions that do not match its original proportions stretches or squashes it, and on a face that is obvious immediately. Keeping the ratio locked means you choose one number and the other is calculated. Untick the box only when you have been given two exact dimensions and you know the source is already close to that shape — otherwise crop the image first, then resize.
Enlarging is not the same as recovering detail
You can set dimensions larger than the original here, but nothing is gained by it. The extra pixels are interpolated from the ones already present, so the result is a bigger, softer version of the same image. If you need a genuinely larger image, go back to the original file at its full resolution rather than upscaling a copy that has already been shrunk.
Resizing versus compressing
This page changes pixel dimensions. It does not aim at a file size — whatever size falls out is what you get. If you have been given a KB limit instead, use the image compressor, which searches for the quality setting that fits under it.
Your files stay on your device
This page never uploads anything. The image is decoded and re-encoded by a canvas element inside your own browser, so there is no server that receives it and nothing to delete afterwards. It also means the tool keeps working if your connection drops mid-task.
Frequently asked questions
Does resizing reduce the file size too?
Usually yes, as a side effect — fewer pixels means fewer bytes. But it is not aimed at a target, so if you need the file under a specific KB limit use the image compressor instead.
Can I resize to an exact width and height that changes the shape?
Yes. Untick 'Keep aspect ratio' and both boxes become independent. The image will be stretched to fit, so only do this when you know the proportions are close already.
Which output format should I pick?
JPG for photographs and anything going to an upload form. PNG when you need sharp text, line art, or transparency preserved. WebP when file size matters more than compatibility with older software.
What happens to a transparent PNG if I choose JPG?
JPG cannot store transparency, so transparent areas are filled with white. Choose PNG or WebP as the output if you need the transparency kept.
Is there a maximum image size?
No fixed limit, but the work happens in your browser's memory. Very large images can be slow or fail on older phones.