Compress Image

Reduce the file size of any JPG, PNG or WebP without a visible drop in quality — compared live, side by side.

What image compression actually does

Every photo you take carries far more visual data than a screen or a web page needs to look sharp. A compressor rewrites that data more efficiently: it groups similar colors, discards detail the eye barely registers, and rebuilds the file using a smaller set of instructions. The picture that comes out the other side looks the same at a glance, but the file behind it can be a tenth of the size — sometimes smaller.

There are two broad approaches. Lossless compression, the method PNG relies on, repacks the existing pixel data without throwing anything away. Lossy compression, the method behind JPG and WebP, is more aggressive: it selectively removes information you are unlikely to notice, which is how a 6 MB photo can shrink to under 500 KB. This tool lets you control exactly how far that trade-off goes with a single quality slider, and shows you the resulting file size before you download anything.

When you actually need to compress an image

Page speed is the most common reason — every extra megabyte in a hero image adds measurable load time. Email is another: most providers cap attachments around 20-25 MB, and a handful of uncompressed photos from a modern phone can hit that ceiling fast. Compression also matters for anyone paying for storage or bandwidth by the gigabyte, and for online forms that enforce a strict upload limit.

Reading the quality slider

Values above 80% typically show no visible difference from the original for most photos, while giving up a meaningful chunk of file size. The 60-80% range is the sweet spot for everyday sharing — noticeably smaller files with a difference that's hard to spot unless you're zoomed in and comparing side by side. Below 50%, compression artifacts start becoming visible in smooth gradients like skies and skin tones, which is worth watching for if the image will be viewed at full size.

If you need to hit an exact file size — for an upload form with a strict cap — the Compress to Target KB tool automates the same slider by searching for the exact quality that lands under your limit, rather than requiring you to adjust and re-check manually.

Everything runs on your device

The slider recompresses your image live using the Canvas API built into your browser, which is why the result updates instantly as you drag it rather than requiring a separate upload-and-wait step for every adjustment. That immediacy makes it easy to find the exact point where file size drops meaningfully without quality dropping noticeably along with it.

Because nothing leaves your device during this process, it's a safe way to compress sensitive images too — screenshots with personal information, internal documents, or private photos — without a server-side copy ever being created.

Frequently asked questions