Mozilla this week announced that it will support Google's compressed WebP image format in Firefox, leaving Apple's Safari as the one flagship browser without any compatibility.
Mozilla's adoption follows recent news from Microsoft that it will support WebP in Edge, the browser built into Windows 10.
WebP is an offshoot of Google's older VP8 video format. It was announced in 2010 by Google as a new open standard for web-published graphics, offering smaller file sizes for equivalent quality to JPEG. Animation and metadata support was added in 2011, with transparency added in 2012.
Google claims that PNG to WebP conversions result in a 28 percent to 45 percent reduction in file size, depending on the original PNG.
Apple is typically resistant to supporting formats founded by rivals, sometimes to the detriment of the end experience. The Apple TV 4K can't play YouTube videos in 4K resolution, for example, because tvOS is missing Google's VP9 codec.
In 2016, test versions of iOS 10 and macOS Sierra briefly supported WebP, but Apple later backtracked for reasons known only to itself — but are likely related to the company's adoption of HEIF as a standard.
Presently, on the Mac, Pixelmator supports the file format without extension. Support in Photoshop can be added with a third-party extension.