About WebP and AVIF
WebP typically lands 25–35% smaller than JPG at similar quality, supports transparency and animation, and every current browser reads it — which makes it a safe default for the web.
AVIF is the newest of the four, built on the AV1 codec. It usually produces the smallest files, handles transparency and wide color, and is supported by all modern browsers — encoding just takes longer.
Converting WebP to AVIF is lossy — use the quality slider to trade file size against fidelity. Files are converted on the fly and never stored.