AVIF Image Format: The Complete Beginner's Guide
What is AVIF, why it matters, and how to start using it to dramatically reduce image file sizes.
What Is AVIF?
AVIF (AV1 Image File Format) is a next-generation image format based on the AV1 video codec, developed by the Alliance for Open Media (members include Google, Netflix, Amazon, Apple, and Microsoft). It achieves 40–50% smaller file sizes than JPEG at equivalent visual quality — significantly better than WebP's 25–35% savings.
AVIF supports both lossy and lossless compression, HDR, wide color gamut, alpha transparency, and even animation. It is the most efficient image format available today for web use.
AVIF vs JPEG vs WebP: Compression Comparison
Real-world test: a 4000×3000 landscape photo at quality 80:
| Format | File Size | Savings vs JPEG | Encoding Speed |
|---|---|---|---|
| JPEG (q80) | 2.4 MB | — | Instant |
| WebP (q80) | 1.6 MB | −33% | ~100ms |
| AVIF (q80) | 1.1 MB | −54% | ~800ms |
AVIF achieves the smallest file sizes, but takes longer to encode. This makes it ideal for pre-processed images (build-time, batch conversion, CMS upload) rather than real-time on-the-fly transforms.
AVIF Browser Support in 2025
AVIF is supported by all major modern browsers:
- Chrome: Full support since v85 (2020)
- Firefox: Full support since v93 (2021)
- Safari: Full support since v16 (2022)
- Edge: Full support since v121 (2024)
- Opera: Full support since v71 (2020)
Global coverage is now 92%+. For the remaining browsers, use the <picture> element with WebP and JPEG fallbacks.
How to Use AVIF with Fallbacks
Serve AVIF as the primary format, with WebP and JPEG as progressive fallbacks:
<picture>
<source srcset="image.avif" type="image/avif">
<source srcset="image.webp" type="image/webp">
<img src="image.jpg" alt="Description" width="1200" height="800" loading="lazy">
</picture>The browser evaluates each <source> in order and picks the first format it supports. This guarantees every visitor sees an image — and the most efficient one their browser can handle.
When to Use AVIF vs WebP
Choose AVIF when:
- You want the smallest possible file sizes
- Images are pre-processed at build time or during upload
- Bandwidth costs are a major concern (mobile users)
- Optimizing hero images and large photography
- Your audience uses modern browsers
Choose WebP when:
- You need fast encoding for real-time conversion
- Maximum browser compatibility is critical
- Your CDN performs on-the-fly image transforms
- You need animated images (WebP supports animation)
- Serving e-commerce product images at scale
AVIF and SEO
Google explicitly recommends using modern image formats like AVIF as part of Core Web Vitals optimization. Smaller image files lead to faster Largest Contentful Paint (LCP), which is a direct ranking factor. Sites that switch from JPEG to AVIF for hero images often see measurable LCP improvements of 1–2 seconds on mobile connections.
Additionally, faster pages lead to lower bounce rates and higher engagement — indirect signals that further benefit SEO performance.
Convert Images to AVIF for Free
BulkPicConv lets you convert images to AVIF directly in your browser — no upload, no sign-up, no watermark. Drop your images, select AVIF as the output format, and download optimized files in seconds.