What PNG to WebP does
PNG is the format for screenshots, logos and anything with transparency — and it is large. WebP keeps the transparency and cuts the size dramatically: typically 60–80% smaller for screenshots and UI graphics, and far smaller still for photographic PNGs. This converter re-encodes a PNG as WebP at the quality you choose, keeping the alpha channel, entirely in your browser.
Why PNG files are large
PNG is lossless: every pixel is stored exactly, compressed only by finding repetition. That works well for flat colours and hard edges, which is why a simple logo is tiny, but photographs, gradients and drop shadows have almost no repetition and compress poorly. A 1,920 × 1,080 screenshot with a photo wallpaper is often 2–4 MB as PNG and 200–400 KB as WebP at quality 0.8 with no visible difference.
| Content | PNG | WebP (q 0.8) | Notes |
|---|---|---|---|
| Flat logo, 4 colours | 8 KB | 6 KB | Little to gain; either is fine |
| App screenshot with text | 600 KB | 120 KB | Text stays crisp at 0.85+ |
| Screenshot with photo background | 3 MB | 300 KB | Big win |
| Photo saved as PNG | 8 MB | 500 KB | Should never have been PNG |
| Transparent product cut-out | 1.5 MB | 150 KB | Alpha preserved |
Quality settings and text
- 0.9 (default) — safe for screenshots with small text; edges stay sharp.
- 0.8 — photos, cut-outs, graphics without fine text.
- Below 0.75 — visible softening on text; fine for thumbnails.
- Lossy WebP compresses the alpha channel too; at very low quality, soft transparent edges can become ragged. Keep transparent images at 0.85 or above.
Transparency is preserved
WebP supports an 8-bit alpha channel like PNG, so a logo on a transparent background, a product cut-out or a UI element with soft shadows converts cleanly and sits on any background in the browser. This is the main reason to prefer WebP over JPG for graphics: JPG would fill the transparent areas with white.
Common uses
- Shrinking screenshots for documentation sites, help centres and blog posts.
- Converting a folder of PNG product images to cut page weight on an online store.
- Reducing app icons and UI assets in web apps.
- Sharing screenshots in chat and email where a 3 MB PNG is unwelcome.
- Preparing transparent overlays and stickers for the web.
When to keep PNG
- The destination does not accept WebP — older software, some CMS uploaders, email signatures.
- The image will be edited further; PNG is the safer lossless master.
- Pixel-perfect requirements — pixel art, icons at exact sizes, images used for automated visual comparison.
- Tiny images where the saving is a few hundred bytes.