What is AVIF? The Complete Guide to the AVIF Image Format

Introduction to AVIF

AVIF (AV1 Image File Format) is a modern, open-source image format that delivers significantly smaller file sizes than traditional formats like JPG and PNG while maintaining excellent visual quality. Developed by the Alliance for Open Media (AOMedia) — a consortium that includes Google, Apple, Microsoft, Amazon, Netflix, and Mozilla — AVIF is rapidly becoming the preferred format for web images.

If you've ever struggled with balancing image quality against page load speed, AVIF might be the answer you've been looking for. In this guide, we'll cover everything you need to know about the AVIF format: its origins, technical underpinnings, browser support, and practical advice on when and how to use it.

A Brief History of AVIF

AVIF is based on the AV1 video codec, which was itself developed by the Alliance for Open Media as a royalty-free alternative to proprietary video codecs like H.265/HEVC. AV1 was finalized in 2018, and the image format derived from it — AVIF — was formalized shortly after.

The Alliance for Open Media was founded in 2015 by Amazon, Cisco, Google, Intel, Microsoft, Mozilla, and Netflix. Their goal was to create an open, royalty-free video coding format. Apple joined the alliance in 2018, which was a significant milestone for widespread adoption. The AVIF specification is maintained under the MPEG-4 Part 12 (ISO Base Media File Format) container, making it compatible with the broader ecosystem of media standards.

The first browser to support AVIF was Google Chrome, which added support in version 85 (released August 2020). Firefox followed in late 2021, and Apple's Safari added support in 2023. This rapid adoption by all major browsers signaled that AVIF was ready for mainstream use.

How AVIF Compression Works

AVIF uses the AV1 codec's intra-frame coding tools to compress still images. Without diving too deep into the mathematics, here's a high-level overview of how it achieves such impressive compression:

• Block-based coding: The image is divided into blocks (called "superblocks" in AV1), which can range from 64x64 to 128x128 pixels. These blocks are then subdivided recursively based on image content, allowing the encoder to allocate more detail to complex areas and fewer bits to simple ones.
• Intra prediction: AVIF uses sophisticated prediction modes to estimate pixel values based on neighboring pixels that have already been decoded. This reduces the amount of new information that needs to be stored.
• Transform coding: After prediction, the residual (the difference between the predicted and actual pixels) is transformed using DCT (Discrete Cosine Transform) or ADST (Asymmetric Discrete Sine Transform) and then quantized to further reduce data.
• Entropy coding: The final step uses arithmetic coding to represent the quantized data as efficiently as possible, squeezing out the last bits of redundancy.

The result is an image format that can achieve 50% smaller file sizes than JPG at equivalent visual quality, and roughly 20-30% smaller than WebP. AVIF also supports both lossy and lossless compression, giving you flexibility depending on your needs.

Key Features of AVIF

High Dynamic Range (HDR)

AVIF supports HDR content with up to 12-bit color depth and wide color gamuts. This makes it suitable for photography and creative work where accurate color reproduction matters. Formats like JPG are limited to 8-bit color depth, which means AVIF can represent over 68 billion colors compared to JPG's 16.7 million.

Transparency (Alpha Channel)

Unlike JPG, AVIF fully supports transparency through an alpha channel. This makes it a viable alternative to PNG for images that require transparent backgrounds — but at a fraction of the file size.

Animation

AVIF supports animated image sequences, similar to GIF and animated WebP. Because it uses AV1's efficient compression, animated AVIF files are dramatically smaller than equivalent GIFs while supporting full color depth and transparency.

Film Grain Synthesis

One unique feature of AVIF is its support for film grain synthesis. Rather than encoding the actual grain pattern in each frame (which consumes many bits), the encoder can describe the grain characteristics parametrically. The decoder then synthesizes matching grain during playback. This is particularly useful for photographic images where preserving a natural grain texture is desirable.

Browser Support

AVIF support has matured significantly since 2020. Here's the current state of browser compatibility:

As of late 2025, AVIF is supported by all major browsers, covering well over 95% of global web users. For the small percentage of users on older browsers, you can use the <picture> element to serve JPG or WebP as a fallback.

Pros and Cons of AVIF

Advantages

• Superior compression: AVIF consistently delivers the smallest file sizes among widely-supported formats, often 50% smaller than JPG and 20-30% smaller than WebP at comparable quality.
• Excellent image quality: AVIF handles gradients, textures, and fine details particularly well, with fewer compression artifacts (like banding or blockiness) than older formats.
• Royalty-free: Unlike HEIF/HEIC (which uses the patented HEVC codec), AVIF is completely royalty-free, making it safe to use in any project without licensing concerns.
• Rich feature set: HDR, wide color gamut, transparency, animation, and film grain synthesis are all supported in a single format.
• Broad browser support: All major browsers now support AVIF natively.

Disadvantages

• Slower encoding: AVIF encoding is computationally intensive and can be significantly slower than JPG or WebP encoding. This is its most notable drawback.
• Limited software support: While browser support is excellent, many desktop applications (image editors, viewers) still lack native AVIF support. Adobe Photoshop, for example, has been slow to add full AVIF integration.
• Maximum resolution limits: The base AVIF specification limits images to 8,193 x 4,320 pixels per tile. Larger images require tiling, which not all decoders handle correctly.
• Progressive decoding: AVIF does not support progressive loading the way JPG does. The entire file must be downloaded before the image can be displayed, which can affect perceived performance on slow connections.

AVIF vs JPG vs PNG vs WebP

Here's how AVIF stacks up against the other major image formats:

In short, AVIF offers the best compression and the richest feature set, but comes at the cost of slower encoding and slightly less universal support. For most web use cases, the file size savings make AVIF the best default choice.

When to Use AVIF

AVIF is an excellent choice in the following scenarios:

• Website images: If page speed matters to you (and it should — Google uses Core Web Vitals as a ranking factor), AVIF's small file sizes directly translate to faster load times and better Largest Contentful Paint (LCP) scores.
• Photography portfolios: AVIF's superior handling of gradients and fine detail makes it ideal for photographic content.
• E-commerce product images: Hundreds of product images on a single page? AVIF can cut your image bandwidth in half without any visible quality loss.
• Images with transparency: AVIF is a much more efficient replacement for PNG when you need transparent backgrounds.

AVIF may not be the best choice when:

• You need maximum compatibility with legacy systems or older software.
• You're working with print workflows that require formats like TIFF or high-quality JPG.
• You need progressive image loading for users on very slow connections.
• Encoding speed is critical (e.g., real-time image processing pipelines).

Practical Tips for Working with AVIF

Converting Existing Images

If you have existing images in JPG format and want to convert them to AVIF, you can use our free JPG to AVIF converter. The conversion happens entirely in your browser — no files are uploaded to any server, so your images stay private.

Going the other direction? If you've received AVIF files and need them in a more universally compatible format, our AVIF to JPG converter makes it simple. Just drag and drop your files and download the converted JPGs.

Using AVIF on Your Website

The recommended approach for serving AVIF images on the web is to use the HTML <picture> element with fallbacks:

<picture>
  <source srcset="image.avif" type="image/avif">
  <source srcset="image.webp" type="image/webp">
  <img src="image.jpg" alt="Description">
</picture>

This approach serves AVIF to browsers that support it, WebP as a second choice, and JPG as the universal fallback. The browser automatically selects the best format it can handle.

Quality Settings

When encoding AVIF images, a quality setting of 60-70 (on a 0-100 scale) typically produces results that are visually indistinguishable from a JPG at quality 85-90, but at roughly half the file size. Start with quality 65 and adjust based on your specific content.

The Future of AVIF

AVIF is well-positioned to become the dominant image format on the web. With backing from every major tech company, royalty-free licensing, and measurably superior compression, adoption will continue to grow. As encoding tools become faster and more software adds native support, the remaining friction points will diminish.

For now, the best approach is to use AVIF as your primary web format with JPG fallbacks, and to convert between formats as needed using tools like our AVIF to JPG and JPG to AVIF converters.