JPG vs PNG vs WebP: Which Image Format Should You Use?

What each format actually does to your pixels

JPG is lossy by design: it divides the picture into small blocks and discards fine colour variation the eye is least sensitive to. That is why it excels on photographs, where every pixel differs slightly from its neighbour, and why it struggles with text, logos and line art — hard edges pick up faint halos (ringing) that get worse as the quality setting drops. JPG has no alpha channel, so transparent areas must be filled with a solid colour before saving.

PNG is lossless: the decoded image is identical to what was saved, every time, no matter how often you re-save it. It shrinks files by finding repetition — long runs of the same colour, repeated patterns — which is exactly what a screenshot, a chart or a flat logo contains and exactly what a photo does not. PNG also carries full 8-bit transparency, which is why cut-out product shots and UI assets use it.

WebPoffers both a lossy mode and a lossless mode, both with transparency. Google's own figures put lossy WebP noticeably smaller than JPG at comparable quality, and lossless WebP smaller than PNG. The price is compatibility: every current major browser decodes WebP, but older desktop software, some email clients and many upload forms still expect JPG or PNG.

Mixed content: a photo with text on it

Marketing images are usually both — a photograph with a headline laid over it — and no single format is ideal. Lossy JPG softens the lettering; lossless PNG balloons because of the photo underneath. The practical compromise is a high-quality JPG (85–90%) or lossy WebP if the destination supports it, with the text kept reasonably large so the slight softening is invisible at display size. For a web page you control, serve WebP and let the browser fall back to a JPG copy for the handful of clients that cannot decode it; for an upload form or an email, pick whichever of JPG or PNG the receiving system lists.

Converting between them: what to watch

Going from a lossy format to a lossless one never recovers detail — a JPG saved as PNG is a pixel-perfect copy of the already-degraded JPG, only much larger. Going the other way, from PNG to JPG, you must decide what replaces the transparent pixels; Image Studio asks for a background colour (white by default) whenever JPG output is selected, because JPG would otherwise render those areas black. Re-saving a JPG as JPG applies the lossy step again, so convert from the best original you have rather than from a previous export.

One more subtlety: the same quality number means different things in different encoders. A phone camera's 90% and a browser canvas's 90% are not the same file size or the same look, so compare outputs by eye and by size rather than by the slider position. For one-off conversions there are focused tools for WebP to JPG, JPG to WebP, PNG to WebP and HEIC to JPG; all of them run in your browser.