JPG converter
JPG is the lowest common denominator of images, in the best sense: every browser, OS, photo frame, government upload form and ancient desktop app accepts it. These converters take you into JPG when compatibility is the goal and out of JPG when you need transparency, lossless editing or smaller modern files.
What is JPG?
JPG (or JPEG, for the Joint Photographic Experts Group that standardized it in 1992) is the most widely supported image format ever shipped. It uses lossy DCT compression tuned for photographs, which buys small files at the cost of discarding fine detail, and it has no transparency support. Practically everything that can open an image can open a JPG.