Compress images online
Reduce a photo's file size by adjusting the quality and the maximum width. Unlike other services, the image is processed entirely in your browser: it is never uploaded to any server.
How compression works without a server
Compressing an image means cutting its weight in megabytes without it looking noticeably worse. This tool does it inside your own browser: the image is drawn onto an invisible canvas and saved again at a lower quality or a smaller size. It never goes up to a server, which means a personal photo or a sensitive document never leaves your device.
Quality or dimensions: two ways to slim a photo
There are two levers. One is lowering the compression quality, which in formats like JPEG drops detail the eye barely notices; going from 100% to 80% quality usually cuts the weight a lot with minimal visible loss. The other is reducing the pixel dimensions: a photo 6,000 pixels wide is huge to email or put on a website, and bringing it down to 1,500 leaves it perfect for screen. Often the most effective approach is to combine the two.
Why you want it to weigh less
A light image sends faster by email or messaging app, doesn't run into the size limits of official forms (which often ask for under 1 or 2 MB) and makes a web page load faster, something visitors and Google both appreciate. For printing it's worth keeping more resolution; for viewing on screen, you can almost always get away with far less than the original carries.
Loss you can't undo
It's worth knowing that lossy compression is irreversible: once the quality is lowered, that information doesn't come back. So it's a good idea to keep the original and work on a copy, especially for a photo you'll later want to print or edit.