WebP vs JPG vs AVIF: which should your website use?

The comparison that matters

Numbers vary with the image, but the ordering is stable: AVIF is smallest, WebP next, JPG largest. Transparency support and browser coverage decide which of them you can actually use.

What to actually serve

If you control the markup, serve modern formats with a fallback: AVIF first, WebP second, JPG last. The browser picks the first one it understands, so newer browsers get the smaller file and older ones still see the image. That is a single picture element with two extra source lines, and it is the single highest-value change most sites can make to their image weight.

If you are uploading to a platform that only accepts one file, choose WebP: it is smaller than JPG, keeps transparency, and every current browser displays it. The main reason to still choose JPG is an audience using old software - a printer, an offline editor, a corporate intranet.

Where AVIF wins and where it bites

AVIF compresses hardest at the low quality settings where JPG falls apart, so it is the format for image-heavy pages that must stay light. The costs are real though: encoding is much slower, older software cannot open it at all, and some image editing tools still do not import it cleanly.

One practical catch for browser-based tools: creating an AVIF requires the browser to support AVIF encoding, which today means Chromium browsers. On Firefox or Safari a converter should say so and offer WebP rather than silently producing something else.

Converting between the three

Conversions between lossy formats always cost a little quality, because each save discards detail. Convert from the original master rather than from a previously converted copy, and convert once rather than repeatedly.

Moving from a lossy format to a lossless one - to PNG, for example - makes the file much larger without recovering what was already lost. Do that only when you need to edit and re-save repeatedly, or need transparency.