WebP can be useful for website images because it supports compact encoding and alpha transparency. The right result still depends on the source, chosen quality and the browser or application that will receive it.
Convert Image to WebP creates WebP when the hosting PHP GD build supports the codec. A missing encoder produces a clear error instead of a renamed PNG masquerading as WebP.
Compare the actual file, not an expected saving
Convert a familiar source at a moderate quality and inspect both the preview and the reported bytes. A smaller output is useful only if its detail is acceptable for the intended display.
Dimensions remain unchanged. If a 1200 by 800 photo needs to become 600 by 400, resize it before conversion or use another appropriate preparation step.
Transparent pixels can remain in the output. View the image against its intended page background to check edge blending rather than judging it solely against the preview checker.
Some upload forms accept only JPEG or PNG
A modern website image format is not necessarily accepted by a recruitment or document upload portal. Follow that form's listed formats before choosing a codec.
This tool accepts static JPEG, PNG and WebP input. It is not an animated WebP editor, and animated inputs are rejected. Converting one frame is not silently offered as a substitute.
Original metadata and colour profiles are removed during encoding. Keep an original copy for archival or colour managed work.
Use the download with its real .webp extension and bytes. Then verify it in the receiving system. A successful encoding on Whatson confirms that a WebP file was created, not that every external importer supports the format.
Reference: PHP WebP encoding support.