AVIF (AV1 Image File Format) is one of the most significant advances in image compression since WebP. Based on the AV1 video codec developed by the Alliance for Open Media — a group that includes Google, Apple, Netflix, Amazon, and Mozilla — AVIF delivers dramatically smaller file sizes than both JPEG and WebP at equivalent or better visual quality.
How AVIF Works
AVIF stores image data using the same compression algorithms used to encode AV1 video frames. This is a fundamentally different approach from JPEG, which was designed 30 years ago for the computing resources of the early 1990s. Modern video codecs are far more sophisticated at modelling how the human visual system perceives detail, colour, and texture.
Key features of AVIF:
- Both lossy and lossless compression modes
- Full alpha channel transparency support
- High dynamic range (HDR) and wide colour gamut (WCG) support
- 10-bit and 12-bit colour depth (vs JPEG's 8-bit)
- Animation support (similar to GIF or WebP animations)
- No patent licensing fees — completely open and free
AVIF vs JPEG vs WebP: File Size Comparison
In real-world tests, AVIF consistently outperforms both JPEG and WebP:
- AVIF vs JPEG: AVIF images are typically 50–60% smaller than JPEG at equivalent visual quality
- AVIF vs WebP: AVIF images are typically 20–30% smaller than WebP at equivalent quality
- At lower quality settings, the gap is even larger — AVIF maintains acceptable quality at bitrates where JPEG and WebP show severe artifacts
A photograph that is 200 KB as a JPEG at quality 85% might be 100 KB as a WebP and 80 KB as an AVIF — all at visually similar quality. For a website with hundreds of images, this difference is substantial.
The Trade-off: Encoding Speed
AVIF's main limitation is encoding speed. Encoding an AVIF image is significantly slower than encoding a JPEG or WebP — often 5–20× slower. For a large image library, this can mean hours of encoding time compared to minutes for WebP.
This is primarily a concern for server-side batch processing. For single-image tools like this one, encoding speed is measured in seconds rather than milliseconds, so the difference is not noticeable to the end user. Decoding (viewing) AVIF is fast on all modern devices.
Browser Support in 2025
AVIF browser support has matured significantly:
- Chrome: Full support since version 85 (2020)
- Firefox: Full support since version 93 (2021)
- Safari: Full support since Safari 16 / iOS 16 (2022)
- Edge: Full support since version 121 (2024)
As of 2025, AVIF covers over 95% of global browser usage. The main gap is very old browsers and some email clients, which still do not support AVIF.
When Should You Use AVIF?
- Web images where file size is critical — e-commerce product images, news sites, any page where LCP performance matters
- Images with HDR content or wide colour gamuts — AVIF's 10-bit support preserves more colour information than JPEG
- When you want the smallest possible files without compromising visual quality
- As the primary format in a modern image pipeline with JPEG or WebP fallbacks for older browsers
When to Stick with WebP or JPEG
- When encoding speed matters — WebP encodes much faster than AVIF
- Email images — email clients have poor AVIF support; use JPEG or PNG
- Platforms with specific format requirements (many social media platforms require JPEG or PNG)
- When targeting users on older devices where AVIF decoding hardware acceleration is not available
AVIF in Practice
The typical modern web image workflow in 2025 looks like this: offer AVIF as the primary format in a <picture> element, with WebP as the first fallback and JPEG as the universal fallback. This ensures every user gets the best format their browser supports:
- Modern browsers (Chrome, Firefox, Safari, Edge): serve AVIF for the smallest files
- Older modern browsers: serve WebP for good compression
- Legacy browsers: serve JPEG for universal compatibility
Summary
AVIF is the most efficient image format available for the web in 2025. It delivers smaller files than JPEG and WebP at equivalent visual quality, supports modern features like HDR and transparency, and has excellent browser coverage. The main trade-off is slower encoding. For new web projects and image optimization pipelines, AVIF should be your first choice, with WebP and JPEG as fallbacks.