The three formats solve different problems, and picking the wrong one is the most common reason images look worse than they should or take too long to load. JPG, PNG, and WebP all store the same underlying pixel grid, but they compress it in fundamentally different ways, and that difference decides whether a format is right for a photo, a logo, or a screenshot with text in it.
JPG: built for photographs, not for edges
JPG uses lossy compression tuned for photographic detail: smooth gradients, natural color variation, and the kind of noise a camera sensor produces. It throws away information the human eye is less sensitive to, which works well on a sunset photo and badly on a screenshot with sharp black text on a white background, where JPG's compression creates visible fuzzy halos around hard edges. JPG also has no transparency channel, so it's never the right choice for a logo that needs to sit on different colored backgrounds.
If you're prepping photos for upload, the Compress Image tool lets you dial in the JPG quality level directly and see the size trade-off before you commit, rather than guessing at a percentage.
PNG: lossless, with transparency
PNG compresses without losing any pixel data, which makes it the right choice for logos, icons, screenshots, and anything with flat colors or sharp text where JPG artifacts would be visible. It also supports a true alpha transparency channel, essential for a logo you'll place over varying backgrounds. The trade-off is file size: a PNG of a photograph is often several times larger than an equivalent-quality JPG, because lossless compression can't discard the fine photographic detail that JPG happily throws away.
If you already have a JPG but need transparency, or vice versa, Convert Image handles the format switch directly, and Remove Background can generate a transparent PNG from a photo that currently has a solid background.
WebP: the modern middle ground
WebP supports both lossy and lossless compression in one format, plus transparency, and at equivalent visual quality it typically produces files 25-35% smaller than JPG and significantly smaller than PNG. Virtually every modern browser supports it, which is why most web performance audits now flag JPG and PNG images as an easy win to convert. The main reason not to use WebP everywhere is compatibility with older tools or platforms that specifically require JPG or PNG uploads, like some print services or legacy content management systems.
You can convert an existing image library to WebP with Batch Image Converter instead of doing it one file at a time, which matters once you're dealing with more than a handful of images.