Image Resizer

When you open an image, the width and height boxes show its current size. Change either one and, with the link icon on, the other follows so the picture keeps its shape. The percentage slider (1% to 500%) does the same thing proportionally: 50% halves both sides, which leaves a quarter of the pixels.

Unlocking the ratio lets you type any width and height. The image is then stretched or squeezed to fit, which distorts faces, circles and text. If you need a different shape without distortion, crop first with the Crop tool and then resize, or use a social media preset, which fits the image inside a canvas instead of stretching it.

Downsizing is where resizing pays off. Halving the width and height cuts the pixel count by 75%, and file size usually falls a lot as a result. It is the most effective way to make a large phone photo suitable for a website or email.

Enlarging works, but it cannot add detail. The browser fills in new pixels by blending neighbours, so a 400 px image stretched to 1600 px looks soft. That is a limitation of every interpolation method, not just this one. The Image Upscaler page explains what can and cannot be recovered.

• WebP (default) and JPG are saved at quality 0.92, which keeps most detail while still compressing.
• PNG is saved losslessly by the browser. It is the right choice for screenshots, graphics and anything with transparency, but photos become much larger as PNG.
• Transparency: WebP and PNG keep it. JPG has no transparency, and areas that were transparent come out black, so pick PNG or WebP for logos and cut-outs.
• Metadata: the image is redrawn on a canvas, so EXIF data (including GPS), and the colour profile, are not carried over.

The rotate buttons turn the image in 90 degree steps and the flip buttons mirror it. They are applied in the same pass as the resize, so you only re-encode once. For angles other than 90 degree steps, use the Rotate tool.

• A form asks for exact dimensions: unlock the ratio only if the source already has the same shape; otherwise crop to that shape first.
• A website template wants 1200 px wide images: type 1200 in the width box with the lock on.
• The file is still too heavy after resizing: run it through the Image Compressor or Reduce Image Size.
• You have a whole folder: the Bulk Image Resizer applies the same settings to many files and gives you a ZIP.

The image is decoded and redrawn on a canvas in your browser tab. It is not uploaded. Very large images (tens of megapixels) can be slow or fail on phones because of memory limits in the browser.