image/webp and image/avif — Next-Generation Image Formats
Explore modern image MIME types image/webp and image/avif, their browser support, and how they compare to JPEG and PNG.
Detailed Explanation
Modern Image Formats: WebP and AVIF
Next-generation image formats offer significantly better compression than JPEG and PNG while maintaining comparable visual quality.
image/webp
Developed by Google, WebP supports both lossy and lossless compression, animation, and alpha transparency.
- Extension:
.webp - Lossy size: ~25–35% smaller than JPEG at equivalent quality
- Lossless size: ~25% smaller than PNG
- Browser support: All modern browsers (Chrome, Firefox, Safari 14+, Edge)
image/avif
Based on the AV1 video codec, AVIF achieves even better compression ratios.
- Extension:
.avif - Lossy size: ~50% smaller than JPEG
- Lossless: Supported
- HDR: Supports wide color gamut and HDR
- Browser support: Chrome 85+, Firefox 93+, Safari 16.1+
Comparison Table
| Feature | JPEG | PNG | WebP | AVIF |
|---|---|---|---|---|
| Lossy | Yes | No | Yes | Yes |
| Lossless | No | Yes | Yes | Yes |
| Transparency | No | Yes | Yes | Yes |
| Animation | No | APNG | Yes | Yes |
| HDR | No | No | No | Yes |
| Avg. file size | Baseline | Large | Small | Smallest |
HTTP Content Negotiation
Servers can use the Accept header to serve the best format:
Accept: image/avif, image/webp, image/jpeg
CDNs like Cloudflare and Vercel can automatically transcode images based on browser support.
Use Case
Adopt image/webp as a universal modern replacement for JPEG and PNG. Use image/avif when targeting browsers that support it for maximum compression savings. Implement both with <picture> fallbacks for broad compatibility.