WebP is a new modern image format, developed by Google to be a successor to the common image formats widely being used on the web. It supports adjustable lossy compression, makes it a good replacement for JPEG with a 25-35% smaller final image size with the same visual quality and compression levels. WebP also supports lossless compression and 8-bit alpha transparency channel which makes it a choice to use instead of PNG. About 25% smaller image size is expected for WebP lossless images compared to PNG.
Animated WebP has also some advantages over animated GIF. It supports 24-bit RGB color with an 8-bit alpha channel, compared to GIF's 8-bit color and 1-bit alpha. WebP supports both lossy and lossless compression and a single animation can have combined lossy and lossless frames. That makes animated WebP an excellent choice for animated images created from real-world videos.
On the other hand, common web image formats like JPEG, PNG, and GIF are more compatible and well-supported by web browsers, compared to WebP. So, it's a good idea to use WebP with a fallback to common replacement formats for a safe compatibility result.