Compress
Shrink image file size without visible quality loss. All 2 tools are free, with no sign-up and no watermark.
About compress
Compressing an image means throwing away detail a viewer will not miss. JPEG and WebP do this by simplifying areas the eye is least sensitive to — mostly fine colour variation — and the quality setting decides how aggressive that is. There is no single right number: a photograph of a face survives heavy compression far better than a screenshot of text, where the same setting turns letter edges into mush.
The practical rule is to compress once, from the original. Every save re-applies the loss to an image that has already lost something, and those losses stack. If you resize as well, resize first and compress second — a smaller image needs less aggressive compression to hit the same file size.
Both tools here run in your browser, so the pictures never leave your device. The batch compressor does the same job across a folder at once, which is what you want for a product catalogue or a gallery; the single compressor lets you watch the quality slider against one image and find the setting you will then apply to the rest.
Compress — frequently asked questions
For photographs, a quality setting around 75–85 is usually indistinguishable from the original at normal viewing size while cutting the file to a fraction of it. Below about 60 you start seeing blocky patches in skies and smooth gradients. Screenshots and images containing text need a higher setting than photographs, or a lossless format like PNG.