# Image resizer

> Resize an image to exact pixels or a percentage, with the aspect ratio locked or free. Save as JPG, PNG or WebP. Runs in your browser; no uploads.

Canonical: https://toolspace.tech/image-resizer/
Last updated: 2026-10-25

Resize an image to exact pixels or a percentage, with the aspect ratio locked or free, and save it as JPG, PNG or WebP. It all happens in your browser.

This is an interactive tool that runs in the browser: [open the Image resizer](https://toolspace.tech/image-resizer/) to use it. Nothing typed into it is uploaded.

## Common mistakes

### Unlocking the ratio by accident

With the lock off, a new width alone squashes the image. Turn the lock back on, or set both sides on purpose.

### Enlarging small images

Scaling a 400 px image to 2000 px gives a big, soft picture. Start from the largest original you have.

### Saving photos as PNG

PNG is lossless, so photos get large. Use JPEG or WebP for photos and PNG for screenshots and graphics.

### Forgetting high-density screens

An image shown 400 CSS pixels wide on a 2× display needs about 800 real pixels to look crisp.

## How it works

1. **Open an image:** Drop or pick a JPG, PNG or WebP file. It stays on your device.
2. **Set the size:** Type a width or height in pixels, or a percentage. With the lock on, the other side follows the original shape.
3. **Pick a format and download:** The new dimensions and file size update as you go. Download when it looks right.

## Questions

### Will resizing make my image blurry?

Making an image smaller keeps it sharp: large reductions are done in halving steps with high-quality smoothing, which avoids jagged edges. Making it larger can’t add detail, so enlarged images look soft.

### How do I resize without stretching?

Keep the aspect-ratio lock on. You set one side and the other is worked out from the original proportions.

### Is there a size limit?

Browsers cap canvases at about 16,000 pixels on a side and roughly 16 megapixels in total on some devices, so very large outputs are refused with a message.

### Are my images uploaded?

No. The image is decoded and redrawn in this tab, and the page is blocked from sending data anywhere.

## Related

- [Image compressor](https://toolspace.tech/image-compressor/)
- [Aspect ratio calculator](https://toolspace.tech/aspect-ratio-calculator/)
- [Favicon generator](https://toolspace.tech/favicon-generator/)