Choosing the right image format can significantly reduce your website's page weight and improve load times. WebP and AVIF are the two leading modern formats competing to replace JPEG and PNG on the web. This guide breaks down the key differences so you can choose the right format for your project in 2026.

What Is WebP?

WebP was developed by Google and released in 2010. It uses a compression algorithm derived from the VP8 video codec, supporting both lossy and lossless compression as well as transparency (alpha channel) and animations. WebP is now supported by all major browsers including Chrome, Firefox, Safari, and Edge, making it a safe choice for nearly all web projects.

Compared to JPEG, WebP typically achieves 25–34% smaller file sizes at equivalent visual quality. Compared to PNG, lossless WebP is about 26% smaller.

What Is AVIF?

AVIF (AV1 Image File Format) is based on the AV1 video codec developed by the Alliance for Open Media. It was finalized in 2019 and offers significantly better compression than both JPEG and WebP. AVIF supports HDR, wide color gamut, lossless compression, transparency, and animation.

AVIF typically achieves 50% smaller file sizes than JPEG at comparable quality — around 20–30% smaller than WebP in most real-world tests.

Compression Quality Comparison

In head-to-head compression tests:

AVIF wins at high-quality settings — it preserves more detail with smaller files
WebP wins at lower quality — AVIF can introduce more artifacts at very aggressive compression
Both formats outperform JPEG and PNG significantly at most quality levels
AVIF handles gradients and smooth tones especially well

Browser Support in 2026

Browser support has evolved rapidly:

WebP: Supported in Chrome, Firefox, Safari (since 14), Edge, Opera — over 97% global coverage
AVIF: Supported in Chrome, Firefox, Safari (since 16.4), Edge — around 92% global coverage

Both formats have excellent browser support in 2026. If you need to support very old browsers or legacy systems, always provide a JPEG fallback using the HTML picture element.

Encoding Speed

One of AVIF's main drawbacks has been slow encoding speed. AVIF encoding is significantly more CPU-intensive than WebP encoding, which can slow down image pipelines at build time:

WebP encoding — fast, typically 2–5x faster than JPEG encoding
AVIF encoding — slow with traditional encoders; newer tools (libaom, rav1e, SVT-AV1) have improved this significantly

For large image libraries or real-time image conversion, WebP is more practical. For static images optimized at build time, AVIF's encoding speed is acceptable.

Transparency and Animation Support

Both formats handle transparency and animation, but with differences:

Transparency: Both WebP and AVIF support alpha channels, making both suitable as PNG replacements
Animation: Both support animation as alternatives to GIF; AVIF uses AVIS (AVIF Image Sequence) for animation, while WebP uses its own animation format
For animated images, WebP is more widely supported and better tested for animation use cases

Which Format Should You Use?

The practical recommendation for 2026:

Use AVIF for high-quality photography, product images, and hero images where maximum compression matters and build-time encoding is acceptable
Use WebP for images that need faster encoding, animations, or where you need the widest possible compatibility
Use both with the picture element to serve AVIF to supported browsers and WebP as a fallback
Keep JPEG/PNG fallbacks for any legacy browser requirements

How to Convert Images to WebP or AVIF

You can convert any image to WebP or AVIF for free using the Image Converter tool. Simply upload your JPEG, PNG, or other image file and select your target format. After conversion, use the Image Compressor to fine-tune the quality and file size.

For most web projects in 2026, serving AVIF with a WebP fallback and a JPEG/PNG last resort gives you the best combination of compression performance and compatibility.