Compress JPG, PNG and WebP images to reduce file size and compare the before and after size of each. Handles many images at once, all in your browser.
A quality of 70 to 80 usually looks the same to the eye while cutting the size a lot. To go smaller, lowering the resolution under SIZE costs less quality than dropping the quality setting further.
Already heavily compressed JPGs or simple PNG graphics can grow when saved again. The result shows a + percentage in that case, so keep the original or try WebP.
PNG is lossless, so there's no quality setting and the size barely changes. For photos, save as JPG or WebP to get much smaller files. JPG fills transparent areas with white.
No. Compression happens entirely in your browser and your files are never sent anywhere.