The best web format for graphics with transparency
PNG is the traditional choice for logos, icons and graphics that need a transparent background, but it pays for its transparency and losslessness with large files. WebP offers a way out: it keeps the alpha channel, so transparency is fully preserved, while compressing much more efficiently. For flat graphics and screenshots the result is often dramatically smaller than the PNG and visually identical.
That combination — transparency preserved, size cut sharply — is exactly what makes WebP the strongest format for graphics on the modern web. Converting your transparent PNGs to WebP shrinks them without the white-background compromise that converting to JPG would force, which is why WebP has largely replaced PNG for web use where browser support allows.
This is the reason so many sites now ship WebP by default and keep PNG only as a fallback for the rare old client. If you are preparing graphics for the web today, converting your PNGs to WebP is close to a free win: the images look the same, they carry transparency where they need it, and they weigh a good deal less. For a site with many icons and graphics, that saving across every asset adds up to a noticeably lighter, faster page.
How much smaller, and why
The size reduction depends on the image. Photographic PNGs — which were an inefficient choice to begin with — see the largest savings, sometimes shrinking by well over half. Flat graphics and logos still shrink meaningfully while staying pixel-clean. Screenshots, which sit between the two, usually compress well because WebP handles both smooth and sharp regions better than PNG's lossless-only approach.
The quality slider here uses lossy WebP, which gives the biggest reductions and is the right choice for almost all web images, since the loss is imperceptible at sensible settings. A lossless WebP mode also exists for cases where every pixel must be exact, but for shrinking graphics to load faster, lossy WebP at a high quality is the sweet spot.
Private by design
Your PNGs are converted to WebP by your own browser, with no upload to any server. For unpublished designs, brand assets or anything you would rather not hand to a third-party service, that is the safe path — the file is processed on your device and the result is handed straight back to you, with nothing retained anywhere else.
The tool accepts a batch, so you can convert a set of PNG assets in one go, see the saving on each, and download them together as a ZIP. Everything runs locally, so there is no upload wait and no size limit beyond your device's own memory, and your original PNGs stay exactly where they are.
Lossy and lossless WebP
WebP comes in two flavours, and the distinction matters when converting from PNG. Lossless WebP reproduces the image exactly, like PNG, but usually in a smaller file — a safe choice for graphics where every pixel must be perfect. Lossy WebP discards a little information for a much bigger reduction, and at high quality the loss is invisible.
The quality slider here uses lossy WebP, which is the right default for almost all web graphics because the size saving is large and the visible cost is nil. If you specifically need pixel-exact output — a precise UI asset, a diagram that must not shift a single edge — keep the PNG or use a lossless workflow, but for shrinking images to load faster, lossy WebP wins comfortably.