Resize an Image

Resize an Image is a free tool that runs entirely in your browser, with no data ever sent to a server. Change the width or height in pixels, in batch, keeping proportions.

Choosing the right dimensions

An image displayed at 800 pixels wide gains nothing from measuring 4000. The browser scales it down for display, but your visitor still downloads the entire file. Resizing to the size actually displayed is the single move that lightens a page the most, often more than compression.

A good rule of thumb

Take the intended display width, then double it to stay sharp on high-density screens. An image displayed at 600 pixels should therefore be exported at 1200 pixels wide.

Progressive downscaling

When the reduction exceeds a factor of two, the tool proceeds in successive steps rather than in a single pass. The result is noticeably sharper, especially on text and thin lines.

What this tool does not do

This tool does not read HEIC photos (the default on some iPhones): convert them to JPEG from the device first. On a PNG, compression changes the format rather than truly reducing the size, since the browser cannot produce a reduced-palette PNG.

Frequently asked questions

Can I enlarge an image?

Technically yes, by unchecking "Never enlarge". But no enlargement invents details missing from the original file: the image will look blurry. Start from the original file at full resolution instead.

Are proportions respected?

Yes by default. If you fill in both fields with the box checked, the image is calculated to fit entirely within the requested rectangle, without distortion. Uncheck the box to force exact dimensions.

Are my files sent to a server?

No: processing happens entirely in your browser, on your device. No file is ever transmitted to a server, at any point.