Convert AVIF to WebP

No — that is the whole reason I built this. The conversion runs in your browser using WebAssembly, so your files never leave your device; there is no server in the loop at all. It also means the tool keeps working offline once the page has loaded, and there is no file size limit beyond your device’s memory.

When something in your stack — an older browser you must support, a CMS, an email tool, an image CDN plan — handles WebP but not AVIF. You give up a modest amount of compression and gain years of extra compatibility.

Usually 20–50% larger than the AVIF, which still leaves it far smaller than a JPG or PNG of the same image. I default the quality to 82 to keep this double-lossy conversion visually clean.

Yes — both formats support full alpha transparency, so logos and cutouts convert intact. This is the pair of formats where transparency never gets lost in translation.

WebP if the fallback is for browsers and CMSes: it keeps alpha and stays 3–4× smaller than JPG. AVIF to JPG if the fallback is for humans — attachments, uploads, office documents — because "every current browser" still excludes plenty of software people actually use. Match the fallback to the consumer, not the other way round.

Two honest cases: if everything that touches your images already handles AVIF, you are adding 20–50% more bytes for nothing; and if the AVIF was itself a re-encode, this second lossy pass visibly softens fine texture. In the second case, dig out the true original and convert it fresh instead of laundering the AVIF through WebP.