Image resizer

What is the Image Resizer?

The Image Resizer changes the pixel dimensions of one or more images, either to an exact width and height, a percentage of the original size, or a ready-made social media preset. It handles a single photo or a whole batch at once, with control over how mismatched shapes are handled and, optionally, a target file size to hit.

Everything happens locally in your browser using the Canvas API. Your images are never uploaded to a server, so it's fast and private, and there's no file size charged against a quota.

How to use it

1. Drop one or more images onto the upload area, or click it to browse your device.
2. Choose a resize mode: Custom size for exact pixels, Percentage for proportional scaling, or Social media for a ready-made platform preset.
3. If your target shape does not match an image's original shape, choose how to handle it: crop to fill, stretch, or fit with white, black, or blurred bars.
4. Pick an output format, and either a quality level or a target file size in KB.
5. Click Resize image. A single image downloads directly; multiple images download together as a ZIP.

Custom size vs. percentage vs. social media

Use custom size when you know precisely what pixel dimensions you need. Use percentage to scale proportionally without worrying about exact numbers, this mode never distorts an image since width and height always scale together. Use social media presets to instantly match the exact size a platform recommends, like an Instagram Story or a YouTube thumbnail, without looking up the numbers yourself.

Handling a shape mismatch

• Crop to fill - scales the image up to completely cover the target size, then trims the overflow from the edges. No empty space, but some of the image is cut off.
• Stretch to fit - forces the image to the exact target dimensions, which can distort it if the shapes are very different.
• Fit with white/black bars - scales the image down to fit entirely within the target size, filling any leftover space with a solid white or black background. Nothing is cropped or distorted.
• Fit with blurred background - same as above, but fills the leftover space with a softly blurred, zoomed-in copy of the image itself instead of a solid color, a popular look for turning a landscape photo into a square or vertical post without harsh bars.

Setting a target file size

Instead of picking a quality percentage, you can tell the tool a target file size in kilobytes, useful when you have a strict upload limit, like a 200KB cap on a form or ad platform. The tool searches for the highest JPG quality setting that still lands at or under your target size. This only works for JPG output, since JPG's compression level directly controls file size in a predictable way, PNG and WEBP don't offer the same simple lever.

Resizing multiple images at once

Add as many images as you like, they all appear in a list where you can review or remove any before resizing. The same settings (size, format, quality) apply to every image in the batch. When you click resize, a single image downloads directly, while a batch of several images downloads together as one ZIP file, saving you from clicking download over and over.

Frequently asked questions

Will resizing reduce my image's quality?

Reducing dimensions generally looks sharp, since there's more original detail than the smaller size needs. Enlarging beyond the original size looks softer, since new pixels are being estimated rather than captured originally.

Does the aspect ratio lock work with multiple images?

The lock calculates a matching height from the width you type based on a single image's ratio, so it's most useful with one image loaded. With multiple images of different shapes, set your width and height directly and use the shape mismatch options to control how each image fits.

Why does target file size force JPG output?

JPG's lossy compression scales smoothly with quality, making it possible to search for a setting that lands near a specific file size. PNG is lossless and doesn't compress the same predictable way, so a target size in KB isn't a meaningful option for it.

Can I mix different image formats in one batch?

Yes, you can upload a mix of JPG, PNG, and WEBP files together, the same output format and size settings will apply to all of them.