Image Resizer

How to resize an image

1. Drop one or more images on the drop zone, or click it to choose files. JPG, PNG, WebP, GIF and BMP are accepted, and you can add as many files as you like.
2. Under Resize by, pick Pixels to type an exact Width (px) and Height (px), or Percentage to scale every image by the same amount (for example 50 %).
3. Leave Keep aspect ratio ticked to avoid stretching. With a single image, typing the width fills in the matching height, and vice versa.
4. Choose the Output format: Same as original, JPG, PNG or WebP. For JPG and WebP, set the Quality slider.
5. Click Resize images. Each file gets its own row with a preview, the size before and after, the old and new dimensions, and a Download button. Download all saves every result one after the other.

How the new size is calculated

In Percentage mode, both sides are multiplied by the same factor: a 4000 × 3000 photo at 25 % becomes 1000 × 750 pixels.

In Pixels mode with Keep aspect ratio on:

• If you give only a width, the height is calculated from the original proportions. A 1920 × 1080 image resized to a width of 1280 becomes 1280 × 720.
• If you give only a height, the width follows the same way.
• If you give both, the image is fitted inside that box without distortion. With 800 × 800, a landscape 4000 × 3000 photo becomes 800 × 600 and a portrait 3000 × 4000 photo becomes 600 × 800. This makes batch resizing of mixed orientations easy.

With Keep aspect ratio off, the image is stretched to exactly the width and height you enter; an empty field keeps the original value for that side.

Tick Don’t enlarge smaller images when you want a maximum size only: pictures already smaller than the target are left at their original dimensions instead of being scaled up and blurred.

Quality and file size

Resizing uses a high-quality resampling filter (the “Magic Kernel Sharp” filter of the pica library) rather than the browser’s basic scaling, so downsized photos stay sharp without jagged edges. Reducing the dimensions is the most effective way to shrink a file: halving the width and height leaves a quarter of the pixels, which usually cuts the file size by 60 to 75 %.

For photos, JPG or WebP at 80–90 % quality is a good choice. PNG is lossless and best for screenshots, logos and graphics with flat colors or transparency. When JPG is chosen, transparent areas are filled with white. GIF and BMP files keep only their first frame and are saved as PNG when Same as original is selected.

Privacy and metadata

Your files never leave your device: decoding, resizing and encoding all happen in your browser, and nothing is uploaded. Because every image is redrawn and re-encoded, the result does not carry the original EXIF metadata such as camera model, date or GPS location. The orientation stored by your phone is applied before resizing, so pictures come out the right way up.