PNG vs JPEG vs WebP: which to convert to
How the three output formats differ on transparency, compression, and support, so you can pick the right target every time you convert an image.
Lossless versus lossy compression
PNG uses lossless compression, meaning the decoded pixels are identical to the original every time, which is ideal for logos, icons, screenshots, and anything with hard edges or text. JPEG and WebP are lossy: they discard fine detail the eye is unlikely to miss in exchange for much smaller files. That trade is controlled by the quality slider, where lower values compress harder and can introduce blocky artifacts or fuzzy edges. For photographs the loss is usually invisible at high quality, but repeatedly re-saving a lossy file degrades it further each time.
Transparency and the alpha channel
PNG and WebP both carry an alpha channel, so a pixel can be fully or partly see-through, which is essential for overlay graphics and logos placed on colored backgrounds. JPEG has no alpha at all, so any transparency must be flattened onto a solid color before the file can be written. That is why this tool shows a background color picker only when the JPEG target is selected. If you convert a transparent PNG to JPEG on white and later place it on a dark page, the former transparent area will appear as a white box.
File size and browser support
At a given visual quality WebP is typically the smallest of the three, often noticeably smaller than an equivalent JPEG, and it also supports transparency, which makes it a strong default for the web. JPEG remains the most universally accepted format for photos and is safe anywhere. PNG is larger for photographic content but unbeatable for crisp graphics. Every current major browser can display all three, though some older software and a few messaging apps still handle WebP inconsistently.
Picking a target for the job
Choose PNG when you need perfect fidelity or transparency and file size is secondary, such as UI assets and screenshots. Choose JPEG when you want a photo to open reliably everywhere and do not need transparency. Choose WebP when you are optimizing images for a website and want the smallest download while keeping transparency. When in doubt, convert once to each and compare the Change box, since the best answer depends on the specific image.