PNG to WebP converter, free and no upload

The case where this makes the file bigger

There is one PNG that comes out of here bigger than it went in, and it is worth knowing which before you convert a folder of them. PNG has a palette mode: instead of storing a colour for every pixel, the file holds a list of up to 256 colours and then stores an index into that list. Screenshot tools, icon exporters and anything drawing flat interface graphics use it constantly, and it is brutally efficient — a 400-pixel icon in palette mode can be under 2 KB.

WebP has no equivalent. It re-describes the picture in full colour, and 2 KB of indexes becomes several kilobytes of encoded image data. Nothing is wrong; the two formats simply have different best cases, and a picture that is already living in PNG’s best case has nothing to gain by leaving it.

This page will do it anyway if you ask, because a converter that second-guesses you is worse than one that does what it was told. It writes lossy WebP at a fixed quality of 90 out of 100 and hands you the result, whatever it weighs. The image compressor is the tool with the opinion: it compares the result against the original and refuses to give you a file that got bigger.

One more choice sits behind this page. WebP also has a lossless mode, and this tool does not use it — a lossless WebP of a PNG is smaller than the PNG but only modestly, and the reason people arrive at this page is a large reduction with the transparency intact. If you specifically need bit-exact output, the honest answer is to stay on PNG rather than to switch formats and lose the guarantee anyway.

What the WebP keeps

Transparency is preserved, including soft edges.
The file gets much smaller in almost every case. Flat graphics and illustrations gain the most; photographs saved as PNG gain enormously.
Very old software will not open it. This is a conversion for files headed to the web, not for a file you are about to hand to an unknown person.

The format the web overuses

PNG is the format the web overuses. It gets picked because it is safe and lossless, and then a page ends up carrying several megabytes of images that could have been a few hundred kilobytes with nothing visibly different.

WebP is the direct replacement, because it does the one thing that used to force the choice: it stores transparency. Before WebP, wanting a transparent background meant accepting PNG file sizes.

For interface assets, icons and illustrations, this conversion routinely takes 70 to 90 percent off the file with no visible change.

Converting a PNG to WebP

WebP is already selected above.
Drop your PNG images in, or click to browse.
Download the result. It never left your device.

Flat icons already saved in PNG’s palette mode are the one input worth checking afterwards; everything else gets smaller.

PNG and WebP, side by side

Is WebP lossless like PNG?

It can be, but this page writes lossy WebP at quality 90, which is what makes it small. For flat graphics the difference is usually invisible. If you need bit-exact output, stay on PNG.

My WebP came out bigger than the PNG. Why?

The PNG was almost certainly in palette mode — up to 256 colours stored as indexes, which is extremely compact for flat graphics. WebP has no palette mode and has to describe the picture in full colour. Keep the PNG.

Will search engines penalise WebP images?

The opposite. Google recommends modern formats and measures page speed as a ranking signal. Smaller images help.

What about AVIF?

AVIF is smaller again, especially for photographs, and also keeps transparency. It is newer, so support outside browsers is thinner. WebP is the safer choice of the two today.

The other two places a PNG can go

PNG to JPG For the screenshot that is too big to attach.
HEIC to WebP Keeps HEIC-like file sizes, but the web can actually read it.
JPG to WebP Roughly a third off a photo, with no visible change.

Or open the image converter to pick any combination, and the image compressor when the problem is size rather than format.

PNG to WebP converter