How this converter works
Your browser decodes each AVIF with its built-in decoder, redraws it on a canvas, and exports a PNG. PNG is lossless, so the output contains exactly the decoded pixels, alpha channel included. Nothing is uploaded anywhere; the page keeps working offline once loaded.
When PNG is the right target
Pick PNG when the AVIF has transparency to preserve (logos, icons, cutouts) or when it is a sharp-edged graphic where JPG compression would smear text and lines. The cost is file size: PNG is the heaviest common format. For photos that just need to open everywhere, the AVIF to JPG converter produces far smaller files.
Why AVIF files keep appearing on your disk
AVIF compresses harder than WebP and much harder than JPG, so image CDNs serve it to save bandwidth. Right-click, save image, and the file is .avif: perfect for the site that served it, useless for the editor that refuses it. Browsers have decoded AVIF since around 2020 to 2022; the rest of the software world is still catching up, and until it does, converting a copy is the two-click fix.