PNG to WebP Converter

PNG to WebP, run entirely on your device with no upload: the converter reads each PNG in your browser tab and re-encodes it to WebP locally, so nothing is transmitted to a server. Most people who land here are web developers, site owners, and designers trying to cut PNG file weight to speed up a site (better Largest Contentful Paint and Core Web Vitals) while keeping transparency intact. This tool does exactly that, with a verifiable no-upload guarantee that server converters structurally cannot offer.

What this conversion actually does (and does NOT do)

WebP supports an 8-bit alpha channel (256 levels of opacity) just like PNG, so transparency is fully preserved when you convert. That holds for the lossy WebP this page writes, which is the opposite of JPG (also written jpeg), a format that has no alpha channel and would flatten your transparency onto a solid background. If your PNG has a transparent background, your WebP will too.

WebP has two modes. Lossless WebP keeps the exact pixels (Google reports it roughly 26% smaller than PNG at default settings), while lossy WebP discards some detail for much smaller files. This page encodes lossy WebP, using your browser's built-in encoder at the quality slider value, because that is where the big savings are. Lossless WebP only appears as an automatic fallback when your browser cannot encode lossy WebP: a note tells you when that happens, and the slider then has no effect. If you need a pixel-identical copy, keep the PNG.

Lossy WebP can cut a PNG by up to roughly 80%, but it discards detail, so the biggest wins come from PNGs that are really photographs or large screenshots where slight softening is acceptable. For line art, logos, and UI with sharp edges, low settings introduce ringing and blur artifacts, so use quality 90 or above there, or keep the PNG. The counterintuitive part: a 24-bit photographic PNG with no transparency is the worst case for PNG's DEFLATE compression and the best case for WebP, so those files see the biggest savings.

One hard limit to know: WebP maxes out at 16383 x 16383 pixels, so a PNG larger than that cannot become a single WebP. The browser encoder also works at 8 bits per channel, so a 16-bit PNG is reduced to 8-bit. Conversion can also drop ancillary PNG chunks such as some metadata or an embedded color profile, which is a privacy plus for screenshots but worth checking if you depend on an exact ICC color profile for color-critical work.

When to choose PNG to WebP vs the alternative

WebP is the right target when your goal is a lighter, web-friendly image that still needs transparency, because it gives you PNG-grade alpha at a fraction of the bytes. Use quality 80-90 when the PNG is actually a photo or a big screenshot and maximum size reduction matters more than a perfectly identical pixel grid; for logos, icons, or UI elements, push the slider to 90-95, or keep the PNG if every pixel must match. If a viewer ever needs to edit the result back into a layered or universally-supported raster, you can reverse the process anytime with the WebP to PNG converter. For a broader set of inputs and targets, the general image converter handles JPG, AVIF, BMP, and TIFF as well.

How to convert

1. Drop one or many PNG files into the converter; they are read locally in your browser, never uploaded.
2. The output format is pre-selected to WebP. Use the quality slider to pick your trade-off: 90-95 for near-lossless results, 75-85 for the web sweet spot on photographic PNGs.
3. Transparency is carried through automatically, so PNGs with an alpha channel produce WebP files with the same transparency.
4. Click Convert. A single file downloads directly; multiple files download together as a ZIP, with no count cap.

No upload. It runs on your device.

Your browser decodes the PNG and its built-in canvas encoder writes the lossy WebP, all inside your browser tab. If the browser cannot encode lossy WebP, a Rust module compiled to WebAssembly writes a lossless WebP instead. There are zero network requests for your file: the PNG bytes go from your disk into memory, through the encoder, and straight back to a download. After the page loads once, it works offline. There is nothing to delete afterward because nothing was ever uploaded, and you can confirm all of this yourself by watching the DevTools Network tab during a conversion. This matters because PNGs are often confidential design assets, product mockups, and internal app UI screenshots that should never touch a third-party server.

No limits

Unlimited batch conversion, no file-size cap, no daily quota, no watermark on the output, no sign-up, and no ads. Convert one PNG or a few hundred in one pass.

Frequently asked questions

Does converting PNG to WebP lose quality?

Some, because this page encodes lossy WebP. At quality 90-95 the difference is hard to see on most images, and lower settings trade more detail for up to roughly 80% size savings. The only exception is the automatic lossless fallback used when a browser cannot encode lossy WebP, which keeps every pixel.

Does WebP keep PNG transparency (the alpha channel)?

Yes. WebP has a full 8-bit alpha channel with 256 opacity levels, matching PNG, so transparency survives the conversion. The lossy WebP this page writes keeps it, unlike JPG (jpeg), which has no alpha and would flatten transparency onto a solid color.

How much smaller is WebP than PNG?

Google reports lossless WebP around 26% smaller than PNG at default settings. The lossy WebP this page produces usually goes much further, up to about 80% off a photographic PNG, and 24-bit photo-like PNGs without transparency tend to show the largest reductions.

Does this converter offer lossless WebP?

No. It always encodes lossy WebP at the slider quality, and lossless WebP only appears as an automatic fallback when your browser cannot encode lossy WebP. For logos, icons, line art, and UI with sharp edges, use quality 90 or above to avoid ringing and blur, or keep the PNG if it must stay pixel-identical.

Can I convert multiple PNG files to WebP at once (batch)?

Yes, drop as many PNGs as you like and they are all converted in one pass. A single file downloads directly, while multiple files come back as a ZIP, with no file-count cap and no upload bandwidth needed.

Is converting PNG to WebP reversible?

Not exactly. Lossy WebP discards detail that cannot be recovered, so converting back with the WebP to PNG converter simply rebuilds a PNG from the already-reduced pixels. Keep your original PNG if you may need it again.

Do all browsers support WebP?

WebP has had roughly 95-97% browser support since about 2023, covering Chrome, Firefox, Safari 14 and newer, Edge, and Opera. For the small share of legacy clients, serve WebP inside a <picture> element with a PNG fallback.

Is it safe to convert confidential PNGs to WebP online?

Yes, because nothing is uploaded: the conversion runs locally in your browser (its built-in WebP encoder, with a Rust/WebAssembly fallback), with zero network requests for the file. That makes it GDPR-trivial and well suited to confidential mockups, internal screenshots, and unreleased brand assets, and you can verify it in the DevTools Network tab.

Will converting PNG to WebP improve my website's Core Web Vitals?

Switching site images from PNG to WebP cuts total image bandwidth by roughly 30-40%, which directly improves Largest Contentful Paint, a Core Web Vitals ranking signal. Smaller images load faster, so pages render sooner and feel more responsive.

Why is my WebP sometimes larger than the original PNG?

This happens most often with tiny images, already heavily-optimized PNGs, or simple graphics where PNG's DEFLATE compression is already near-optimal and WebP's container overhead works against you. In those cases the original PNG may be the better choice, or you can lower the quality slider to force a size reduction.

Is there a file size or daily conversion limit?

There is no daily quota and no imposed file-size cap, since processing is local rather than queued on a server. The only practical ceiling is WebP's maximum dimensions of 16383 x 16383 pixels, beyond which an image cannot fit into a single WebP.

Related tools: reverse the conversion with the WebP to PNG converter, drop quality further with the image compressor, or browse every option in the image tools hub.