Convert PNG to WebP — Free, Fast & Private
WebP can replace a PNG without giving up transparency, and it can be lossy or lossless. Everything runs in your browser — nothing is uploaded.
Transparency survives
WebP carries an alpha channel, so a transparent PNG stays transparent. This is the main reason to pick WebP over JPG for logos, icons and cut-out product shots. The measured table below includes a transparent file so you can see the effect on size.
Lossy by default, lossless on request
With the Smart preset the output is lossy, which is where most of the saving comes from. If the PNG is pixel art or a screenshot where every pixel matters, choose the Gentle preset for higher quality. Check the result card: it shows the new size beside the old one, and flags the rare file where WebP came out larger.
You get a real WebP on every browser
Safari cannot write WebP from a canvas, so MiniPx uses its own WebAssembly WebP encoder on every browser. The file you download is a genuine image/webp, not a PNG renamed. Support for displaying WebP starts at Safari 14 (2020); older apps and some print and editing tools still cannot open it.
Animated PNG
An animated PNG (APNG) is converted as a still: only the first frame is written, and the tool says so. MiniPx does not produce animated WebP.
Photographs, logos and screenshots behave differently
A flat logo or a screenshot with large areas of one colour often shrinks a lot, because flat areas compress well. A photograph saved as PNG shrinks even more under lossy WebP, at the cost of fine detail. The measured table below uses real files of both kinds, so read the row closest to yours rather than a headline percentage.
Check the WebP against the PNG before you save
Each row shows the original size, the new size, the change and the output dimensions. A before and after slider lets you inspect edges, especially around transparent cut-outs. If a small PNG came out larger as WebP, the row says so, and you should keep the PNG.
Next steps
Not sure WebP is the right target? The WebP converter lists every WebP direction, and the PNG converter covers JPG, AVIF and PNG outputs.
PNG to WebP on real files: measured sizes
| File | Before | After | Change | Background |
|---|---|---|---|---|
| Phone photo saved as PNG (2016 × 1512) | PNG · 2016 × 1512 px · 6.00 MB | WebP · 2016 × 1512 px · 613.5 KB | 10.0× smaller | — |
| Screenshot (PNG) | PNG · 1280 × 800 px · 88.1 KB | WebP · 1280 × 800 px · 28.5 KB | 3.1× smaller | — |
| Signature on transparency (PNG) | PNG · 2041 × 617 px · 42.3 KB | WebP · 2041 × 617 px · 23.6 KB | 44% smaller | Kept transparent |
| App icon on transparency (PNG) | PNG · 2048 × 2048 px · 162.5 KB | WebP · 2048 × 2048 px · 67.9 KB | 2.4× smaller | Kept transparent |
Measured 2026-10-07 in Chromium 145.0.7632.6 by running this page's converter with its default setting (WebP) on each file. The photos and scans are CC0 or public-domain files from Wikimedia Commons; the screenshot is MiniPx's own; the photo PNG is the phone photo halved and saved as PNG; the transparent signature is the scanned signature with its paper made transparent; the app icon is drawn by the measuring script, with a soft shadow so partial transparency is tested. Sizes are shown as the tool shows them (1 KB = 1,024 bytes).