Mozilla evaluated WebP in October and found its improvements dubious compared to alternatives: http://people.mozilla.org/~josh/lossy_compressed_image_study_octo

Mozilla evaluated WebP in October and found its improvements dubious compared to alternatives: http://people.mozilla.org/~josh/lossy_compressed_image_study_october_2013/ http://people.mozilla.org/~josh/lossy_compressed_image_study... That said, they explicitly did not rule out including WebP in the future. They just concluded it wasn't yet ready. It looks like it may be getting closer to being ready.