PNG to WEBP

PNG's problem is that it refuses to discard anything, which is exactly right for a working file and wasteful for a web asset. A screenshot or a product cut-out saved as PNG routinely runs into the megabytes, and on a page with a dozen of them the cost is severe. WebP solves this without forcing you to give up the alpha channel, which is what makes it strictly better than the old workaround of converting to JPG and painting a fake background behind the transparency. You get soft edges, drop shadows and anti-aliased text intact, at roughly a quarter to a half of PNG's size. The trade-off to understand is that WebP's lossy mode is genuinely lossy, so a screenshot of small text can pick up faint smearing if you push the quality slider too low.

Photographic content tolerates aggressive compression because the eye does not track individual pixels in a texture. Sharp-edged content — UI screenshots, text, diagrams, line art — is the opposite: compression artefacts cluster around high-contrast edges and show up as a faint halo or blur. If your PNG contains readable text, stay at 0.90 or above and check the result at 100% zoom before running a batch.

Both formats store a full 8-bit alpha channel, so this conversion does not flatten anything or ask you for a background colour. Semi-transparent pixels stay semi-transparent, which means soft shadows and feathered edges survive intact. This is the main reason to choose WebP over JPG when your source is a PNG.

Keep PNG when the file is a master copy you will edit again, when it is going into a context that does not decode WebP — email templates are the notorious one, since several desktop mail clients still cannot render it — or when it is a tiny icon where the saving is a few hundred bytes and not worth the extra format in your pipeline. PNG also remains the right answer for anything needing pixel-exact fidelity, such as a QR code or a technical diagram.

PNG is a lossless format built in 1996 as a patent-free replacement for GIF. Nothing is discarded when it compresses, so an image can be opened and re-saved indefinitely without degrading, and it carries a full alpha channel for soft-edged transparency. That fidelity costs space: a photograph stored as PNG is typically several times larger than the same photo as JPG, which is why PNG is the right choice for screenshots, logos and line art rather than camera output.

WebP is Google's 2010 image format, and it is unusual in offering both lossy and lossless modes plus transparency in a single container. In practice it lands roughly 25–35% smaller than an equivalent-quality JPG, which is why it spread quickly across the web once Safari added support in 2020. Its weakness is outside the browser: plenty of desktop software, older phones and printing workflows still will not open a .webp file.