Convert PNG images to WebP for smaller file sizes -- free, private, browser-based
Read more: PNG to WebP Converter
PNG is what designers export. WebP is what browsers want. This converter bridges that gap in three steps, entirely in your browser.
Nothing leaves your machine. The conversion runs in-browser using the Canvas API, so it is safe for unreleased designs, client work, and anything you would rather not send to a third-party server.
The savings from PNG to WebP are not marginal. They are dramatic. Here is what real-world conversions look like:
| Image Type | Typical PNG Size | WebP Size | Savings |
|---|---|---|---|
| Screenshot (1920x1080) | ~800 KB | ~200 KB | 75% |
| UI mockup with transparency | ~1.2 MB | ~350 KB | 71% |
| Icon sprite sheet | ~50 KB | ~15 KB | 70% |
| Product photo (transparent bg) | ~2 MB | ~500 KB | 75% |
| Diagram/illustration | ~400 KB | ~90 KB | 78% |
For a typical page with 8-10 PNG assets, switching to WebP can shave 2-4 MB off total page weight. That directly improves Largest Contentful Paint, reduces bandwidth costs, and makes a noticeable difference on mobile connections.
PNG users reach for PNG because they need pixel-perfect output. Good news: WebP has a lossless mode that preserves every single pixel while still compressing roughly 26% smaller than PNG. That is not a theoretical number -- it is Google's published benchmark across their test corpus.
In this tool, setting quality to 100 activates lossless mode. The output is bit-for-bit identical to your PNG in terms of visual content, just wrapped in a more efficient container.
When to use lossless (quality 100): Pixel art, technical diagrams, UI screenshots where text clarity matters, and any image you plan to edit further downstream. Lossless means no generation loss, so you can convert back to PNG later without degradation.
When lossy is fine (quality 75-90): Marketing banners, hero images, blog graphics, and anything displayed at less than its native resolution. At quality 85, the differences from the PNG source are invisible to the human eye, but the file is 70-80% smaller.
If you work with PNGs, you probably rely on alpha channels. Transparent backgrounds, semi-transparent overlays, soft drop shadows with variable opacity -- these are the reason you are using PNG instead of JPG in the first place.
WebP handles all of this. Both lossy and lossless WebP support full 8-bit alpha channels, which means 256 levels of transparency per pixel, exactly like PNG. Your transparent backgrounds survive the conversion.
Lossy WebP with transparency: The RGB color data gets lossy compression while the alpha channel can be compressed independently. The result is a much smaller file that still has clean, sharp transparency edges. This is something JPG simply cannot do.
Lossless WebP with transparency: Every pixel, including every alpha value, is preserved exactly. This is the safest option if your transparency has subtle gradients or anti-aliased edges that need to stay precise.
Bottom line: if your PNG has transparency, the WebP output from this tool will too. No special settings required.
This converter is built for quick one-offs and testing quality settings before you commit to a pipeline. But for production workflows where you are converting hundreds of PNGs at build time, you will want automated tooling:
cwebp -q 85 input.png -o output.webp for lossy or cwebp -lossless input.png -o output.webp for lossless.sharp('input.png').webp({ quality: 85 }).toFile('output.webp'). Fast, reliable, widely used in build scripts and serverless functions.A practical workflow: use this tool to find the right quality setting for your image type, then apply that setting across your build pipeline. Spending two minutes testing quality 75 vs 85 vs 95 here can save you from shipping oversized assets or over-compressed ones.
File size: WebP produces significantly smaller files at every compression level. Lossless WebP is ~26% smaller than PNG. Lossy WebP at quality 85 is typically 70-80% smaller.
Decoding speed: WebP decodes slightly slower than PNG in raw benchmarks, but the smaller file size means faster network transfer, which dominates total load time on real connections.
Browser support: WebP works in Chrome, Firefox, Safari (14+), Edge, and Opera -- over 97% of global browser share. The only holdouts are IE11 and very old Safari, neither of which represents meaningful traffic for most sites.
Fallback strategy: If you need to support pre-Safari 14, use the <picture> element with a PNG fallback: <picture><source type="image/webp" srcset="image.webp"><img src="image.png"></picture>.
Yes. WebP supports full 8-bit alpha channels in both lossy and lossless modes. Every transparent pixel in your PNG carries over to the WebP output unchanged.
Quality 100 activates lossless compression -- every pixel is preserved identically, with files roughly 26% smaller than PNG. Quality 85 uses lossy compression, producing files 70-80% smaller than PNG with differences that are invisible at normal viewing distances. For web delivery, 85 is the sweet spot. For archival or further editing, use 100.
Yes, use the WebP to PNG converter. If you used lossless WebP (quality 100), the round-trip is perfect. If you used lossy compression, the lost detail cannot be recovered -- keep your original PNG if you might need it.
AVIF can compress even smaller than WebP, but it encodes much slower and has narrower browser support (no Safari before 16.0). For PNG-source images -- especially those with transparency -- WebP is the pragmatic choice today. It is fast to encode, universally supported, and the size savings over PNG are already substantial.
Positively. Smaller images improve page load speed, which directly affects Core Web Vitals scores. Google has explicitly recommended WebP as a format for web images. Faster pages rank better, all else being equal.