AVIF vs WebP vs JPEG: Which one actually wins?
The Performance Breakdown
I tested these against original files ranging from 500KB to 12MB. To keep the comparison fair, I used settings that look identical on a 2x retina display: JPEG (q85), WebP (q80), and AVIF (q65).
- JPEG (q85): Avg size 820 KB. Baseline.
- WebP (q80): Avg size 480 KB. Roughly 41.5% smaller than JPEG.
- AVIF (q65): Avg size 310 KB. Roughly 62.2% smaller than JPEG.
For standard photography, AVIF is the clear winner for payload. On a typical product page with six images, switching from JPEG to AVIF reduces the page weight by about 3MB. On a 10 Mbps connection, that's the difference between a 4-second load and a 1.5-second load.
Graphics and Screenshots
PNGs behave differently. If you need pixel-perfect accuracy for text-heavy screenshots, lossless PNG compression is still the safest bet. However, for UI mockups or illustrations:
- Original PNG: 1.4 MB
- Lossless PNG: 640 KB
- WebP (q80): 180 KB (Visually identical, not pixel-perfect)
- AVIF (q65): 120 KB (Similar visual quality to WebP)
The Trade-off: Encoding Latency
The massive file size savings of AVIF come with a heavy compute cost. AVIF is significantly slower to encode than the alternatives:
- JPEG: 0.3s per image
- WebP: 0.8s per image
- AVIF: 2.5s per image
If you are running a static site generator, encoding at build time is a non-issue. But for platforms handling massive amounts of user-generated content in real-time, WebP is the practical sweet spot.
Implementation Strategy
For e-commerce or high-traffic sites, the most efficient AI workflow for image delivery is using the <picture> element to serve AVIF to the 93% of browsers that support it, with a WebP fallback.
<picture>
<source srcset="image.avif" type="image/avif">
<source srcset="image.webp" type="image/webp">
<img src="image.jpg" alt="Product Image">
</picture>For general blogging, just sticking with WebP at 80% quality provides the best balance of compatibility and speed without the encoding overhead of AVIF.