Why AVIF Sizing Matters

  • AVIF's compression advantage compounds with right-sizing — wrong dimensions waste both bytes and the format edge
  • Mobile data plans benefit most from AVIF — sub-100KB hero images become normal
  • Lighthouse and PageSpeed flag oversized images regardless of format
  • AVIF decode is CPU-heavier than JPEG — oversized AVIF taxes low-end devices

AVIF Resize Best Practices

  • Resize AVIF to actual rendered size, not 2× or 3× density (decode cost matters)
  • Pair AVIF with JPEG fallback in picture element for older browsers
  • Quality 70–80 is the AVIF sweet spot — quality 90+ erases the format advantage
  • Skip AVIF for tiny assets under 5KB — encoding overhead exceeds the saving
  • Always test perceptual quality on actual content, not synthetic samples