PNG to WebP Converter

PNG is the right format for logos, icons, screenshots and anything with transparency, but the files are big. WebP keeps the alpha channel and, in lossless mode, every single pixel, while usually cutting the size a lot. This converter turns PNGs into WebP in your browser with a quality setting, a lossless switch, an optional max width and batch conversion. Your files are never uploaded.

How to use this tool

1. Choose one or more PNG files.
2. Turn on Lossless for logos, icons, UI screenshots and pixel art, so edges and text stay perfectly crisp.
3. Leave it off for photos and illustrations saved as PNG, and set the quality (80 is a good start).
4. Optionally set a max width, convert, and compare each WebP with the original PNG.

Formula

Size change = (WebP bytes ÷ PNG bytes − 1) × 100%

Lossless WebP (VP8L) uses spatial prediction, a colour cache and LZ77-style back-references; Google reports it about 26% smaller than PNG on average. Lossy WebP stores colour with VP8 and keeps transparency in a separate, losslessly compressed alpha plane, so soft shadows and anti-aliased edges survive. The browser's own encoder is used where it exists; Safari has none, so there the page falls back to libwebp in WebAssembly (about 30 MB, downloaded once).

Example

A 547 × 726 px palette logo PNG of 35.5 KB became a 27.5 KB lossless WebP (−22.5%) with identical pixels, and a 23 KB lossy WebP at quality 80. A photo saved as a 2.3 MB PNG typically shrinks by 80–90% as lossy WebP, because PNG is a poor format for photographs.