Convert PNG to WebP
Convert your PNG images to the modern WebP format for faster web performance while preserving transparency.
How to convert PNG to WebP — 3 steps
- 1
Add your PNG files
Drop in one image or a batch. Encoding runs on your own machine, so converting a folder of large screenshots is limited by your processor rather than an upload queue.
- 2
Choose lossless or lossy
Lossless WebP reproduces the PNG exactly and still saves roughly a quarter of the size. Lossy WebP goes much further and suits photographs, where the discarded detail is invisible.
- 3
Download the WebP files
Save the results and compare them against the originals. Your PNGs are untouched, so you can re-run at a different setting if the first attempt cuts too far.
Why WebP replaced PNG for most web images
WebP was designed to do what PNG and JPG each do well, in a single format. Like PNG it supports an alpha channel, so transparency survives conversion — the reason it is a safe swap for logos, icons, and cut-out product shots that would be ruined by JPG. Unlike PNG it also offers a lossy mode, so photographic images can be compressed the way JPG compresses them, only more efficiently.
The savings are real rather than marginal. Lossless WebP typically produces files around 25–30% smaller than the equivalent PNG, and lossy WebP commonly lands 25–35% below a JPG of comparable visual quality. On an image-heavy page that is the difference between a site that feels immediate and one that visibly assembles itself, which is why page-speed tooling flags PNG photographs and recommends WebP almost every time.
Support is no longer the objection it once was. Every current browser — Chrome, Firefox, Safari, Edge, and the mobile versions of each — decodes WebP natively, and has for years. For anything served over the web, the format decision is now straightforward.
Where WebP is still the wrong choice
The gap is outside the browser. Plenty of desktop software, older image viewers, print workflows, and corporate document systems either cannot open a WebP or will not preview it. If the image is going to be emailed to a colleague, dropped into a slide deck, attached to a form, or handed to a printer, PNG or JPG remains the safer currency — a file nobody can open has no size advantage worth having.
There is a subtler trap with the lossy mode. Because WebP handles transparency, it is tempting to use lossy WebP for logos and screenshots on the assumption that transparency support means it suits flat-colour graphics. It does not: lossy compression softens hard edges and text in WebP for the same reason it does in JPG. For anything with lettering or crisp lines, choose lossless — you still get a smaller file than the PNG, with no degradation at all.
Finally, treat conversion as one-way whenever you use the lossy mode. Converting the result back to PNG restores a lossless container but not the discarded detail, and the resulting file will usually be larger than the WebP while looking no better. Keep the original PNG as your master and generate WebP copies for delivery.
Your files never leave your device
Encoding happens in your browser, so unreleased designs, client work, and screenshots containing internal information are converted without being sent to anyone's server.
Most online PDF sites upload your document to their servers, process it there, and keep a copy for minutes, hours, or longer. PilotPDF works differently: the page downloads a small processing engine into your browser, and your file is opened and edited in your device's memory using WebAssembly. Nothing is transmitted, so there is nothing for a server to store, leak, or scan. You can even disconnect from the internet after the page loads and the tool keeps working.
Read more about how this works in our privacy-by-design explainer.