Is AVIF Smaller Than WebP?

When comparing modern image formats like AVIF and WebP, a key question for web developers and content creators is whether AVIF files are typically smaller than WebP files at similar visual quality. This matters because smaller image files help pages load faster, reduce bandwidth usage, and improve performance on both desktop and mobile devices.

How AVIF and WebP Compress Images

Both AVIF and WebP use modern compression techniques that are more efficient than older formats like JPEG. However, they work in slightly different ways:

AVIF uses compression technology derived from the AV1 video codec, which is designed to pack image data into very small files while preserving detail when possible.
WebP uses compression techniques based on an earlier video codec and generally does not achieve the same level of compression efficiency as AVIF.

These differences in compression design mean that when targeting the same visual quality, AVIF usually produces smaller files than WebP.

Typical File Size Differences

In real‑world scenarios where images are compressed to equivalent perceived quality, AVIF often produces noticeably smaller files than WebP:

AVIF files can be 20–30% smaller than WebP for detailed photographs or images with complex gradients and textures.
For images with lots of color information or subtle details, the difference in file size becomes more significant.

For example, a WebP version of a high-resolution photograph might be 600 KB, while the AVIF version at similar visual quality could be around 420–480 KB.

Why AVIF Often Compresses Smaller

AVIF’s efficiency comes from several technical strengths:

Advanced Prediction and Transformation: AVIF reduces redundancy in image data more effectively using modern algorithms.
Higher Color Depth Support: AVIF handles deeper color ranges efficiently, which helps preserve quality in rich images.
Efficient Entropy Coding: The way AVIF encodes statistical image data generally results in smaller files compared to WebP.

These capabilities allow AVIF to outperform WebP on complex, high-detail images that are common on modern websites and blogs.

When WebP Might Be Smaller

There are certain scenarios where WebP can be competitive:

Simple graphics or icons: For images with flat colors or simple shapes, the size difference may be minimal, and sometimes WebP can produce slightly smaller files.
Different compression settings: If WebP is compressed at a higher quality setting while AVIF uses a lower setting, the file sizes may not follow the usual pattern.

However, when both formats are optimized for similar visual quality, AVIF generally produces smaller files.

Implications for Web Usage

Using AVIF can provide tangible benefits for web performance:

Pages can load faster, particularly on image-heavy websites.
Users on mobile networks or with limited bandwidth benefit from reduced data usage.
Smaller image files contribute to improved performance metrics, such as faster rendering and smoother user experiences.

Since WebP has broader support across browsers, many workflows deliver both formats—AVIF for modern browsers and WebP as a fallback for older ones.

Balancing File Size and Compatibility

A practical strategy for serving images effectively on the web includes:

Offering AVIF versions for browsers that support it to take advantage of smaller file sizes.
Providing WebP versions as a widely supported alternative.
Including JPEG or PNG fallbacks for legacy environments that cannot display AVIF or WebP.

This approach ensures that all users see optimized images while maintaining compatibility across devices and browsers.

In summary, AVIF is generally smaller than WebP at equivalent visual quality, making it a strong choice for modern image delivery when combined with careful compatibility planning.