Is AVIF really smaller than WebP?

Generally yes, by around 20-30% at matched visual quality. The advantage is largest on images with gradients and flat colour, and smallest on dense noisy texture where neither codec can do much.

Is it worth converting WebP to AVIF?

It depends on what you are optimising for. If page weight is critical and you can serve an AVIF with a WebP fallback, yes. If you want one file that works everywhere with fast encoding, staying on WebP is a perfectly good decision.

Convert WebP to AVIF

Both are modern formats, so this is a smaller step than converting from JPEG: expect roughly 20-30% off at matched quality. Worth doing when you are chasing the last of your page weight budget and can accept AVIF's narrower support and much slower encoding.

Best for: Squeezing an already-optimised WebP library further when every kilobyte counts.

What to know

Re-encoding lossy WebP into lossy AVIF stacks two generations of loss. Use quality 60 or above to keep that invisible.
The saving is real but modest compared to converting from JPEG or PNG. Consider whether the slower encode and narrower support are worth it.
Metadata in the source WebP will not carry over, as AVIF metadata writing is not yet supported.

About WebP

Google's 2010 format, now the pragmatic default for the web: meaningfully smaller than JPEG and PNG, and supported everywhere that matters.

Slightly behind AVIF on compression at the same visual quality.
Some older desktop software and print pipelines still will not open it.

Support:: All current browsers, including Safari 14+ and Edge. Roughly 97% of users.
Transparency:: Full alpha, in both lossy and lossless modes.

About AVIF

Built on the AV1 video codec and standardised in 2019 — currently the strongest compression available in a widely supported still image format.

The best quality-per-byte of any format here, typically by a wide margin.
Handles gradients and flat colour without the banding JPEG produces.
Wide colour gamut and HDR support built in.
Full alpha, and it compresses that alpha well.

Support:: Chrome, Edge, Firefox, Opera and Safari 16+. Roughly 93% of users.
Transparency:: Full alpha, efficiently compressed.

Frequently asked questions

Is AVIF really smaller than WebP?: Generally yes, by around 20-30% at matched visual quality. The advantage is largest on images with gradients and flat colour, and smallest on dense noisy texture where neither codec can do much.
Is it worth converting WebP to AVIF?: It depends on what you are optimising for. If page weight is critical and you can serve an AVIF with a WebP fallback, yes. If you want one file that works everywhere with fast encoding, staying on WebP is a perfectly good decision.

Related conversions

Converting from something else? Convert any image to AVIF