WEBP vs AVIF — The New Format Challenging WEBP's Dominance

WEBP was the dominant next-gen image format for the last decade. Now AVIF is here with even better compression. Should you switch?

Format Comparison

File Size Comparison

We tested the same 4MP landscape photo across formats:

At quality 85, AVIF is 35% smaller than WEBP. At quality 75 (still visually excellent), AVIF is 66% smaller than the original JPG.

Winner: AVIF for file size.

Browser Support

This is where WEBP wins.

Global AVIF support is around 80–85%. WEBP support is 97%+.

For web use, WEBP is the safer choice. AVIF is the choice when you can control the environment (e.g., serving different formats based on browser detection).

Encoding Speed

AVIF has a significant weakness: encoding is slow. Extremely slow compared to WEBP.

• WEBP encoding: ~50ms for a 4MP image
• AVIF encoding: ~2–5 seconds for a 4MP image

For server-side conversion, this matters. AVIF takes 20–100x longer to encode than WEBP.

For ImageConvert's use case: We serve pre-converted formats, not real-time encoding. Encoding time doesn't affect users.

When to Use Each

Use AVIF when:

• You're serving content to Chrome/Firefox users (80%+ of web traffic)
• You have control over browser detection (can serve AVIF to supported browsers, WEBP fallback for others)
• Maximum compression is the priority
• You can preprocess images (not real-time)

Use WEBP when:

• You want maximum compatibility with minimal complexity
• You can't implement format negotiation based on browser detection
• You need fast encoding (though for web-serving, this is rarely an issue)
• You're targeting a general audience including older browsers

Implementation with Fallback

<picture>
  <source srcset="photo.avif" type="image/avif">
  <source srcset="photo.webp" type="image/webp">
  <img src="photo.jpg" alt="Description">
</picture>

This serves AVIF to browsers that support it, falls back to WEBP, then falls back to JPG.

The Bottom Line

• Right now, WEBP is the practical choice — good compression, near-universal support, fast encoding
• AVIF is better on compression but limited support and slow encoding
• Both are better than JPG — either is a massive improvement over traditional formats

For most web projects, convert to WEBP. If you're serving Chrome-heavy audiences (tech users, modern web apps) and can implement format detection, AVIF is the better choice.