How to compress an image
Drop one or more images on the tool above and press “Compress images”. Each file is re-encoded at the quality you pick, and you get a download link next to each one. Nothing is uploaded — the compression happens in your browser.
Why image size matters
A single phone photo can be 4–8 MB. Put ten of them on a web page and the page takes seconds to load; most visitors leave before it finishes. Email has the same problem: attachments over 10–25 MB are often refused. Compressing photos to a few hundred kilobytes each fixes both problems, and at quality 0.80 the difference is usually invisible.
Choosing a quality setting
Quality 0.80 is the sweet spot for photos. It typically cuts a JPEG to a quarter of its size with no visible change. Quality 0.50 halves the size again but can blur fine detail — fine for thumbnails, risky for a photo you want to print. Quality 0.92 is for images where detail matters and size does not. When in doubt, try 0.80 first and zoom in to check.
Formats: JPG, PNG, and WebP
JPG is for photos; PNG is for graphics with sharp edges and transparency; WebP is the modern middle ground. PNG output is lossless, which means it cannot shrink the way JPG can — for a PNG, most of the saving comes from scaling the image down, not from the quality slider. Converting a photo from PNG to JPG or WebP usually cuts the size by 70% or more. If you need transparency, keep PNG or WebP: JPG has no transparency, so clear areas become white.
When to scale down too
Resolution matters as much as quality. A 4000 px wide photo displayed at 800 px on a website is five times larger than it needs to be. Set the “max side” option to the size the image will actually be shown at — 1600 px for a blog hero image, 800 px for a product thumbnail — and the file shrinks dramatically before quality even comes into it.