Image Resizer

Resize any image to exact pixel dimensions or a percentage of the original. Lock the aspect ratio, pick PNG, JPEG or WebP and download.

Resizing happens entirely in your browser. Your image never leaves your device.

Drop an image here

PNG, JPG, WebP, GIF · up to ~50 MB

How Resizing Works

Resizing is really two operations: resampling the pixels to a new grid, then re-encoding the result into a fresh file. This tool does both locally with the browser's Canvas API — the original file is decoded, drawn onto a target-sized canvas, and written out in the format you choose.

Resampling (bilinear smoothing)
Each destination pixel is a weighted average of the neighboring source pixels. With imageSmoothingQuality set to high, edges and gradients stay smooth when scaling down, and the image fills the target grid cleanly when scaling up.
Why the file is re-encoded
An image file's data is laid out for its exact dimensions, so any size change forces a fresh encode. That means the output size depends on the new dimensions, the format and (for JPG/WebP) the quality setting — shrinking a photo to 800 px wide at quality 85 will usually be a fraction of the original size.
Choosing a format
PNG is lossless and keeps transparency, so it suits screenshots, logos and line art. JPEG is the smallest for photos but has no alpha channel — transparent areas become white. WebP sits in between: lossy or lossless, with transparency and usually better compression than both.

Frequently Asked Questions

How does the resizer actually resize my image?

The browser's Canvas API resamples the original pixels onto a new, target-sized grid. With imageSmoothingQuality set to high, each destination pixel is computed by bilinear interpolation — a weighted average of the nearest source pixels — which keeps edges and gradients looking smooth instead of blocky.

Why does the file get re-encoded?

Changing the pixel dimensions breaks the original file's data layout, so the browser must write out a fresh image file. On preview and download the pixels are re-encoded with the format and quality you picked, which is why the final size depends on both dimensions and quality.

What quality setting should I use?

For JPG and WebP, 80–85 is a sweet spot: files usually shrink dramatically with barely visible quality loss. 90+ is good for print or archival use; 60–75 works well for thumbnails and previews. Quality is ignored for PNG, which is lossless.

Is transparency preserved?

Yes, as long as you keep the output as PNG or WebP, both of which support alpha channels. If you choose JPEG, transparent areas are flattened onto a white background because JPEG has no alpha channel.

What files can I use and what is the size limit?

PNG, JPG, WebP and GIF up to about 50 MB. GIF files are resized as a single still frame — animation is not preserved. Everything runs locally in your browser, so nothing is ever uploaded.