Huzzah! Here’s the scoop:
We are excited to announce that Photoshop now has full support for the WebP file format! WebP files can now be opened, created, edited, and saved in Photoshop without the need for a plug-in or preference setting.
To open a WebP file, simply select and open the file in the same manner as you would any other supported file or document. In addition to open capabilities, you can now create, edit, and save WebP files. Once you are done editing your document, open Save As or Save a Copy and select WebP from the options provided in the file format drop-down menu to save your WebP file.
To learn more, check out Work with WebP files in Photoshop.