How to open a WebP file

Every browser already opens WebP. The trouble starts when you hand one to something older. Here is how to convert it without losing anything you care about.

You already can

Every current browser displays WebP: Chrome, Firefox, Safari, Edge. So does Windows Photos, macOS Preview and Quick Look, and every current phone. If you double-click a .webp file on any machine bought in the last few years, it opens.

The problem is almost never opening one. It is that something else will not take it: an older version of Photoshop, a print shop's upload form, a document template, a piece of internal software that was written when WebP did not exist.

Convert it, and pick the right target

To PNG if the image has transparency, or is a logo, a screenshot, or

line art. Lossless: nothing is lost that was still there.

To JPG if it is a photograph and the file size matters. Lossy, but the

WebP was probably lossy too, so you are not losing the first generation, just adding one.

Converting in a browser means the file is decoded and re-encoded on your own machine, so nothing is uploaded and there is no size limit to bump into.

The one thing to know before converting

WebP comes in two kinds, and they are not labelled differently.

Lossy WebP is the common one: it is what a website serves you, and it is roughly 25-30% smaller than an equivalent JPEG. Converting it to PNG will produce a much larger file that is not one bit better: PNG will faithfully record every compression artefact the WebP already has. If the source was lossy and you only need to view it, converting to JPEG at 90 is the sensible move.

Lossless WebP exists too, and is the right thing to convert to PNG, because there the detail really is intact.

You usually cannot tell which you have by looking. The rule of thumb: if it came off a website it is lossy; if someone exported it deliberately it might not be.

Animated WebP

WebP can hold an animation, like a GIF. Most converters, including browser-based ones, and ours, will take only the first frame, because a canvas holds one image.

If you need the animation preserved, that is a video conversion rather than an image conversion, and a still-image tool is the wrong shape for it.

Why sites use it in the first place

Smaller files at the same visual quality, and it handles both photographs and transparency in one format, so a site does not need JPEG for photos and PNG for logos. That is worth real money in bandwidth at scale, which is why it spread quickly once Safari finally supported it in 2020.

The awkwardness for everyone downstream is the cost of that, and it is gradually going away as older software catches up.

Going the other way

Converting to WebP is worth doing for anything destined for a web page: typically 25-35% smaller than JPEG at a quality nobody can distinguish, with transparency available if you need it.

One caveat, and it is the reason a converter should check rather than assume: a browser that can display a format cannot necessarily write it. Safari displays AVIF and cannot encode it. A converter that offers a format its browser cannot encode will hand you a PNG with the wrong extension, a mislabelled file that fails somewhere further down the line, with no clue where it came from.

Ours tests what the browser can actually encode when the page loads, and greys out what it cannot, with a sentence saying why.