Image Resizer
Runs entirely in your browser. Your files and data never leave your device.
About this tool
Drop in a picture, type the width you want, and download the smaller copy. The height follows automatically so nothing gets stretched, and you can unlock it when you do want to squash a picture into an exact box. A scale menu offers 25%, 50%, 75% and 100% of the original for when you just want it roughly half the size.
How do I pick the right size?
Type a number into the width or height field and the other side updates to keep the proportions. Turn off the aspect ratio lock and the two fields stop talking to each other, which is what you want for a fixed banner slot or an avatar that has to be square. The badge over the preview shows the pixel size and the file size of the result, so you can see straight away whether an email attachment came in under the limit.
The scale menu is a shortcut for the common cases. Picking 50% halves both sides, and the menu switches to “Custom” as soon as you edit a field by hand, so it never claims a percentage that no longer matches. Sides are capped at 20000 pixels, which is well past what browsers can allocate a canvas for. Making a picture bigger than the original works, though the extra pixels are invented by the browser and a small photo blown up will look soft.
Are my images uploaded anywhere?
No. The picture is drawn onto a canvas in the page and re-encoded by WebAssembly codecs running in a Web Worker, all on your own machine. Nothing is sent to a server, so a work document or a photo of your kids is as safe here as it is in your Downloads folder. Re-encoding also drops the EXIF metadata, including the GPS coordinates of where a photo was taken, which is usually a good thing before posting a picture publicly.
Which formats work?
You can open PNG, JPEG, WebP, GIF, BMP and AVIF files. The output can stay in the original format or switch to JPEG, PNG or WebP. GIF, BMP and AVIF inputs come out as PNG when you leave the format on “Keep original”, since those three are not written here.
JPEG and WebP have a quality slider, set to 90, which keeps photos clean at a fraction of the size. PNG has no slider because PNG compression is lossless. The download keeps the original name with the new size appended, so beach.jpg at half size saves as beach-2016x1512.jpg and never overwrites the original.