Convert a PNG to WebP on your Mac
Drag the PNGs into Images by Edmund, choose WebP from the format menu and press Export. Transparency survives the trip. For images going onto a website this is usually a worthwhile saving, but not always, so every card shows what the file will actually weigh before you commit to the change.
macOS 15 or later. Apple silicon Mac. Version 1.1.0, out 11 October 2026. What’s new.
Free, with nothing to unlock and no account.
Convert one right here
Drop a PNG in and get a WebP back, with the transparency intact. It happens in this tab, on your own machine: nothing is uploaded.
Good, and usually a decent saving
Browsers do not agree about what a quality setting means, so this is a dial rather than a number. The size on the result below is the real answer, and it follows the slider.
PNG to WebP, step by step
- Drag the PNGs inA folder of assets is the usual case here. One setting applies across the whole batch, so exporting a site's worth of images is a single pass.
- Choose WebP, and pick lossy or losslessUnder Options, Compression decides. Lossy is the right default for photographs; lossless keeps every pixel and is the one to use on flat graphics and screenshots.
- Press ExportCompare the before and after on each card first. If a particular image comes out larger as WebP, keep the PNG for that one. The app will tell you which.
WebP does not simply beat PNG, and the app will show you where it does not
macOS cannot write WebP at all, only read it, so the app carries Google's own libwebp compiled in rather than doing without the format. That also means the encoder is the reference one rather than an approximation. What it does not mean is that WebP always wins. Measured on two real files: a photograph came out at 62,630 bytes as lossless WebP against 82,376 as an optimised PNG, a clear win, while a four colour flat graphic came out at 3,250 bytes against 924, a loss by more than three times. Nothing in the app picks between them on your behalf, and nothing should. The size on each card is a real encode, so the comparison in front of you is the actual answer for your file rather than a rule of thumb about the format.
Why not just use a converter website?
The images you are converting to WebP are usually the ones about to go live on a site, which means there are a lot of them and they arrive as a folder. Free converter sites are built around the one file case: a queue, a cap, an advert, a download. Doing forty that way is an afternoon.
The other thing a website cannot do is show you the answer before you commit. Here the decision to switch to WebP is made per image, with the real number in front of you, which matters precisely because WebP is not always the smaller of the two.
Questions
Does WebP keep transparency?
Yes, fully. macOS hands the app the PNG's pixels with the alpha channel unmultiplied, and the encoder is told to preserve the colour values sitting underneath fully transparent pixels, which is the detail most converters lose without anyone noticing.
Is WebP smaller than PNG?
Often, but not reliably. Photographs usually shrink; flat graphics with few colours often grow, sometimes a lot. Because every card shows the real figure before you export, you do not have to take a general claim on trust for your particular images.
Lossy or lossless WebP?
Lossless for anything with flat colour, text or sharp edges, so it stays crisp. Lossy for photographs, where it is doing the same job as JPEG and doing it better. Both are in the Compression section under Options.
Do browsers support WebP?
Every current one, and has done for years. The remaining reason to keep a PNG alongside is an old email client or a piece of software that predates it, which is worth checking if the images are going somewhere other than a web page.
Other things it does
There is a full list on the Images by Edmund product page, along with what else the app does.
Get Images by Edmund.
Free, and it does the other eight jobs too. Two ways to get it when it lands: the Mac App Store, or straight from here.
macOS 15 or later. Apple silicon Mac. Version 1.1.0, out 11 October 2026. What’s new.