Most people use whatever image format their phone, camera, or screenshot tool happens to save by default, without ever thinking about it, and most of the time that's fine. But if you've ever wondered why some images load faster than others, why a logo looks blurry after conversion, or why a colleague asked you to "send it as a PNG instead," the answer comes down to a genuine, practical difference between these three formats.
JPG: the default for photos
JPG uses lossy compression, meaning it throws away some detail the eye is least likely to notice in exchange for a much smaller file. For photographs, with their gradual color transitions and natural detail, this trade-off is usually invisible at normal viewing sizes, which is exactly why it's the default format for cameras and phones.
JPG's real limitation: no transparency support, and it handles sharp edges (like text or line art) poorly, compression artifacts show up as blurring or blocky patterns around hard edges, which is why a JPG screenshot of a document often looks slightly fuzzy around the text.
PNG: the default for screenshots, logos, and anything needing transparency
PNG uses lossless compression, every pixel is preserved exactly. This makes it the right choice for anything with sharp edges or flat colors: screenshots, logos, icons, and any graphic with a transparent background. The trade-off is size: a PNG of a photograph is typically much larger than the equivalent JPG, since lossless compression can't take advantage of the same detail-discarding tricks.
WebP: the modern all-rounder
WebP is a newer format that supports both lossy and lossless compression, plus transparency, essentially combining what JPG and PNG each do well into one format. A WebP photo at similar visual quality is typically 20-35% smaller than the equivalent JPG, and a WebP graphic with transparency is often 60-90% smaller than the equivalent PNG.
The only real limitation is compatibility with very old software that hasn't been updated to support it, but every current browser, and most modern image-editing tools, handle WebP natively. For anything destined for the web, it's now the better default over both JPG and PNG.
A simple decision guide
Photo, going on a website: WebP (fallback to JPG only for legacy compatibility needs)
Photo, need maximum compatibility with older software: JPG
Screenshot, logo, or icon with transparency, going on a website: WebP
Screenshot, logo, or icon, need maximum compatibility or a lossless master copy: PNG
Archiving an image you might edit further: PNG (lossless, so no quality is lost before you've even started editing)
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