What is AVIF Format and Why Should You Use It?

The AV1 Image File Format (AVIF) is a modern image format that's rapidly gaining adoption due to its exceptional compression efficiency and visual quality. In this comprehensive guide, we'll explore what AVIF is, its technical capabilities, real-world performance benefits, and why you should consider using it in your projects.

What is AVIF?

AVIF (AV1 Image File Format) is an image format based on the AV1 video codec, developed by the Alliance for Open Media (AOMedia), a consortium that includes major tech companies like Google, Mozilla, Microsoft, Netflix, and Amazon. Released in February 2019, AVIF is designed to be a royalty-free alternative to existing image formats like JPEG, PNG, and WebP.

The format is derived from the keyframes of the AV1 video codec, which itself was designed to be more efficient than previous video codecs like VP9 and H.264. This heritage gives AVIF excellent compression capabilities while maintaining high visual quality.

Technical Deep Dive: AV1 Codec Architecture

Understanding AVIF's technical foundation helps explain why it performs so well. The format leverages the sophisticated AV1 codec, which offers three distinct profiles:

AV1 Profiles and Capabilities

• Main Profile: Supports 8-bit and 10-bit color depth with 4:0:0 (grayscale) and 4:2:0 chroma subsampling. This is the most widely supported profile and sufficient for most web images.
• High Profile: Extends Main profile with 4:4:4 chroma subsampling (no color information loss), ideal for graphics and text.
• Professional Profile: Supports all chroma subsampling modes (4:0:0, 4:2:0, 4:2:2, 4:4:4) with 8-bit, 10-bit, and 12-bit color depths. Perfect for high-end photography and professional workflows.

Color Depth Explained

Bit depth determines how many colors can be represented per pixel. Traditional JPEG uses 8-bit color (256 shades per channel × 3 channels = 16.7 million colors). AVIF supports:

• 8-bit: Standard web images (16.7 million colors)
• 10-bit: 1.07 billion colors - eliminates color banding in gradients
• 12-bit: 68.7 billion colors - professional photography and HDR content

Expert Tip: It's recommended to always use 10-bit encoding even with 8-bit source images. AVIF's internal processing works better with 10-bit color, providing quality improvements with zero compatibility penalty since 10-bit is part of the baseline profile.

Real Compression Benchmarks: AVIF vs Other Formats

Generic claims like "smaller file sizes" don't tell the full story. Here's factual data from real-world testing and major CDN providers:

Real-World Performance Data

These aren't theoretical numbers. Here's evidence from actual implementations:

• imgix (Major CDN): Customers saw an average 60% reduction in file size converting JPEGs to AVIF
• Smashing Magazine Case Study: Achieved 64% page size reduction and 20% LCP improvement by implementing AVIF
• Cloudinary Analysis: AVIF files are 20-30% smaller than WebP at equivalent visual quality
• Mozilla Research: AVIF achieves 50% median compression vs WebP's 30% compression on the same JPEG test set

Practical Example

Converting a high-quality product photo:

• Original JPEG (quality 90): 245 KB
• WebP (equivalent quality): 171 KB (-30%)
• AVIF (equivalent quality): 123 KB (-50%)
• Result: 122 KB saved vs JPEG, 48 KB saved vs WebP

For a site serving 1 million page views/month with an average of 5 product images per page, this translates to 610 GB/month bandwidth savings compared to JPEG.

Browser Support: Current State (2025)

Browser support is critical for adoption. Here's the factual data as of September 2025:

Overall Support: 93.8% of all web browsers (Source: caniuse.com, Sept 2025)

What This Means for Your Site

With 93.8% support, AVIF is ready for production use with proper fallbacks. The 6.2% of users on unsupported browsers (primarily Internet Explorer and old Safari) should be served JPEG or WebP alternatives using the <picture> element.

Performance Impact: Core Web Vitals & Page Speed

Smaller file sizes directly improve Core Web Vitals, Google's key ranking factors. Here's measured data:

Largest Contentful Paint (LCP) Improvements

LCP measures how long it takes for the main content to load. Since images are often the LCP element:

• Baseline (JPEG): LCP at 1.58s
• With WebP: LCP at 1.26s (-20% improvement)
• With AVIF: LCP at 1.26s (-20% improvement) with 64% smaller total page size

Source: Real A/B testing data from production implementations

Mobile Performance Considerations

AVIF decoding is more CPU-intensive than JPEG or WebP. However, the smaller file sizes offset this on mobile networks:

• 4G Connection: 50% file size reduction = 500ms faster download, -100ms slower decode = 400ms net improvement
• 3G Connection: Even more pronounced benefits due to network being the bottleneck
• Hardware Acceleration: Modern GPUs from Nvidia, AMD, and Intel now support AV1 hardware decoding, eliminating the CPU overhead concern

When NOT to Use AVIF (Critical Analysis)

Balanced expertise means acknowledging limitations. AVIF isn't always the right choice:

Legacy Browser Support Required

If your analytics show significant traffic from Internet Explorer or Safari 15 and below, you'll need robust fallbacks, adding complexity to your deployment.

Real-Time Image Manipulation

Encoding AVIF is slower than JPEG or WebP (though decoding is comparable with modern hardware). If you're generating images on-the-fly (e.g., user-uploaded content, dynamic charts), the encoding time might impact user experience.

Simple Graphics and Logos

For simple graphics with few colors, PNG might actually be smaller than AVIF. PNG excels at lossless compression of graphics with solid colors and sharp edges.

Email Marketing

Email clients have poor AVIF support. Stick with JPEG or PNG for email campaigns.

Low-End Mobile Devices (Pre-2020)

Devices from before 2020 without hardware AV1 decoding may struggle with AVIF, causing slower rendering than JPEG. For sites targeting developing markets with older devices, this is a consideration.

Migration Strategy: From JPEG/PNG to AVIF

Here's a practical, step-by-step approach to implementing AVIF on your site:

Step 1: Implement Progressive Enhancement

Use the <picture> element to serve AVIF with fallbacks:

<picture>
  <!-- Modern browsers get AVIF -->
  <source srcset="image.avif" type="image/avif">

  <!-- Fallback to WebP -->
  <source srcset="image.webp" type="image/webp">

  <!-- Final fallback to JPEG -->
  <img src="image.jpg" alt="Description"
       width="800" height="600" loading="lazy">
</picture>

Step 2: Batch Conversion

Convert your existing image library using our AVIF to GIF converter (which also handles JPEG/PNG to AVIF) or command-line tools like FFmpeg.

Step 3: Update Your CMS/Build Process

Configure your CMS or build tools to automatically generate AVIF versions:

• Next.js: Use next/image with AVIF format option
• WordPress: Plugins like ShortPixel or EWWW Image Optimizer
• Custom Build: Add AVIF generation to your image optimization pipeline

Step 4: Testing Checklist

• ✅ Test in Chrome, Firefox, Safari 16+
• ✅ Verify fallbacks work in old Safari, IE
• ✅ Check mobile performance on real devices
• ✅ Validate Core Web Vitals improvements
• ✅ Monitor bandwidth usage reduction

Frequently Asked Questions

Conclusion

AVIF represents a significant advancement in image compression technology, offering proven benefits for web performance and visual quality. With 93.8% browser support and measurable improvements in Core Web Vitals (20-64% performance gains in real implementations), it's ready for production use in 2025.

The key is implementing it thoughtfully with proper fallbacks, testing thoroughly, and monitoring the impact on your specific use case. For most modern websites targeting current browsers, AVIF will provide substantial benefits in page load times, bandwidth costs, and user experience.

When you need to convert AVIF images to more universally compatible formats like GIF, our free browser-based converter makes the process simple and private, with no upload required.