AVIF (AV1 Image File Format) is an open image format developed by the Alliance for Open Media (AOMedia). It stores image data compressed with the AV1 video codec inside an HEIF container. The format was designed to offer better compression efficiency than JPEG, WebP, and PNG while supporting features such as transparency, HDR, wide color gamut, and image sequences.
What Makes AVIF Different?
AVIF is not a minor iteration on JPEG or WebP. It is built on a fundamentally different compression architecture - the AV1 video codec - developed by a broad consortium of technology companies. This gives AVIF a different set of trade-offs compared to older formats: potentially better compression efficiency at the cost of slower encoding, and richer feature support at the cost of greater complexity.
AV1-based compression
AVIF uses the AV1 intra-frame coding tools, which include advanced prediction, transform, and entropy coding techniques. In independent testing by Netflix (2020), AVIF produced substantially smaller files than JPEG at equivalent visual quality for many image types. Results vary significantly with image content, encoder, quality setting, and encoding effort.
HDR and wide color gamut
AVIF natively supports High Dynamic Range (HDR) and wide color gamut (WCG) color spaces including BT.2020. Image items can encode up to 12 bits per sample natively. AVIF 1.2.0 additionally defines Sample Transform Derived Image Items, which allow reconstructing higher-bit-depth precision (up to 16 bits or more) by mathematically combining multiple standard image items - a different mechanism than native 16-bit encoding.
Transparency (alpha channel)
AVIF supports full alpha channel transparency, making it suitable for logos, graphics, and UI elements that require transparent backgrounds. The alpha plane is encoded separately using AV1, which typically produces significantly smaller files than PNG equivalents. See real conversion results for measured file size comparisons on actual graphics.
Open format
AVIF is developed by AOMedia, whose members commit to making patents essential to the specification available on a royalty-free basis under defined terms. The specification document itself is published under the BSD 2-Clause License. As with any technology involving patents, specific implementation and licensing implications should be reviewed for your context. See AOMedia's Patent Licensing Policy for details.
Compare AVIF with Other Formats
Side-by-side comparisons with real images and measured file sizes
View Format ComparisonTechnical Specifications
AVIF uses the HEIF container (ISO/IEC 23008-12) with AV1-compressed image data. The format is standardized as ISO/IEC 23000-22:2025 (second edition, superseding the 2019 original).
| Property | Value |
|---|---|
| File extension | .avif |
| MIME type | image/avif - registered with IANA |
| Container | HEIF / ISOBMFF (ISO/IEC 23008-12) |
| Image codec | AV1 (intra-frame encoding) |
| Color depth | 8, 10, or 12 bits per sample (native). AVIF 1.2.0 defines sample transforms enabling reconstruction of up to 16-bit or higher precision via combined image items - not native 16-bit encoding. |
| Color spaces | sRGB, BT.709, BT.601, BT.2020 (wide color gamut), and others via CICP signaling |
| Chroma subsampling | YUV 4:2:0, 4:2:2, 4:4:4 |
| Image sequences (animation) | Yes - multiple image items with timing metadata |
| HDR / Wide Color Gamut | Yes - BT.2020, PQ and HLG transfer functions supported |
| Transparency (alpha) | Yes - separately encoded AV1 alpha plane |
| Compression modes | Lossy and lossless |
| Transparency | Yes - separate AV1-encoded alpha plane |
| Animation / image sequences | Yes - multiple image items with timing metadata |
| HDR | Yes |
| EXIF / XMP / IPTC metadata | Yes - stored as metadata items in the container |
| ISO standard | ISO/IEC 23000-22:2025 (second edition) |
Browser Support
Static AVIF is supported by all major browsers and reached Baseline status in January 2024, meaning it had been available in all major browser engines for at least a year. For current global usage coverage, consult Can I Use - AVIF.
| Browser | Static AVIF since | Animated AVIF since |
|---|---|---|
| Chrome / Edge | 85 (August 2020) | 85 (August 2020) |
| Opera | 71 (September 2020) | 71 (September 2020) |
| Firefox | 93 (October 2021) | 113 (May 2023) |
| Safari / iOS Safari | 16 (September 2022) | 17 (September 2023, macOS Sonoma / iOS 17) |
AVIF vs JPEG, WebP and PNG
No single format is best for all situations. The table below summarises the key differences; real-world results depend on image content, encoder, quality setting, and encoding effort.
| Feature | AVIF | WebP | JPEG | PNG |
|---|---|---|---|---|
| Compression (lossy) | AV1-based. Often produces smaller files than JPEG or WebP at equivalent visual quality; results vary by content and encoder. | VP8/VP8L-based. Generally smaller than JPEG; widely supported and faster to encode than AVIF. | DCT-based. Widely supported; efficient for photographs. Baseline for comparison. | Lossless compression; often efficient for graphics, screenshots and images requiring exact pixel preservation. No lossy mode. |
| Lossless | Yes | Yes | No | Yes (primary use case) |
| Transparency | Yes | Yes | No | Yes |
| HDR / WCG | Yes (BT.2020, up to 12-bit natively) | Limited (no native HDR signaling) | Limited compared to AVIF | Limited HDR workflow support |
| Max color depth | 8, 10, 12-bit native; 16-bit+ via v1.2.0 sample transforms | 8-bit | 8-bit | 8 or 16-bit |
| Animation | Yes - all major browsers (Safari 17+) | Yes - all major browsers | No | No (APNG is a separate variant) |
| Encoding speed | Generally slower than JPEG or WebP at high-quality settings. Faster presets available with reduced compression efficiency. | Fast | Very fast | Fast |
| Browser support | All major browsers (Baseline 2024) | All major browsers | All browsers | All browsers |
When Should You Use AVIF?
AVIF is generally a good choice when the following conditions apply:
Web delivery of photographs
For photographic content served to modern browsers, AVIF can reduce file sizes meaningfully compared to JPEG, which reduces page weight and may improve loading times. Using the <picture> element with a JPEG fallback maintains compatibility with older browsers.
Transparent graphics and logos
AVIF's alpha channel support combined with AV1 compression can produce significantly smaller files than PNG for transparent graphics. See our sample files for measured results on real conversions.
HDR and wide color gamut content
AVIF is one of the few image formats with standardised HDR and WCG support. For displays capable of rendering HDR content, AVIF can preserve colour information that JPEG cannot.
Bandwidth-sensitive delivery
In contexts where bandwidth cost or mobile data usage matters - such as emerging markets or high-volume image delivery - the file size reduction that AVIF can achieve may be worth the encoding overhead.
Thumbnails and preview images
Netflix, YouTube, and other streaming platforms have adopted AVIF for thumbnail and preview images, where high volume and bandwidth efficiency are important. Netflix's 2020 testing found AVIF better preserved fine detail at lower file sizes compared to JPEG.
Modern web projects targeting current browsers
For projects targeting browsers released since 2022, AVIF can be used confidently with a JPEG or WebP fallback. All major browsers have supported static AVIF since September 2022 (Safari 16).
When AVIF May Not Be the Best Choice
AVIF has real limitations. Understanding them helps avoid applying the format where another option is more appropriate.
Encoding speed is a priority
AVIF encoding is significantly slower than JPEG or WebP, particularly at higher quality settings. If you need to encode images on-the-fly - for example, processing user-uploaded content in real time - AVIF's encoding speed may create a bottleneck. WebP or a fast JPEG encoder may be more practical.
Tooling and ecosystem support
Older image editing software, server-side libraries, or CMS plugins may not support AVIF encoding or decoding. Before adopting AVIF in a workflow, verify that your tools - from editing to CDN to server-side processing - can handle the format reliably.
Simple graphics and diagrams
For images consisting of flat colors, simple shapes, or crisp text - such as diagrams, icons, or illustrations - SVG is typically smaller and resolution-independent. For pixel art or screenshots requiring lossless precision, PNG remains a straightforward choice.
Legacy browser compatibility without fallback
If you cannot implement a <picture> element with a fallback - for example, in certain CMS or email contexts - and must support older browsers, JPEG or PNG may be simpler. AVIF requires Chrome 85+, Firefox 93+, or Safari 16+ for static images.
The file size saving may not justify the change
For some image types - already-compressed JPEGs, very small thumbnails, or images where visual quality is not critical - the file size difference between AVIF and JPEG may be small enough that the conversion effort is not worthwhile. Always test with your actual images before committing to a format change.
High computational encoding cost
At maximum encoding effort, AVIF can be considerably more CPU-intensive than JPEG or WebP. For large-scale encoding pipelines, this has direct cost implications. Evaluate encoding time and infrastructure cost against the bandwidth savings for your specific volume.
How to Use AVIF on a Website
The recommended approach for serving AVIF on the web is the <picture> element, which allows the browser to select the best format it supports while falling back to a universally compatible format:
<picture>
<source srcset="image.avif" type="image/avif">
<source srcset="image.webp" type="image/webp">
<img src="image.jpg" alt="Descriptive alt text" loading="lazy" width="800" height="600">
</picture>This pattern:
- Serves AVIF to browsers that support it (all major browsers since September 2022)
- Falls back to WebP for browsers that support WebP but not AVIF (rare in 2026)
- Falls back to JPEG for older browsers that support neither
- Uses
loading="lazy"for below-the-fold images to reduce initial page load - Includes explicit
widthandheightattributes to prevent layout shift (CLS)
How to Convert Images to AVIF
There are several ways to convert images to AVIF format:
Online converter
AVIF Tools is a free online AVIF converter that lets you convert JPEG, PNG, WebP and HEIC images without installing software - files up to 30 MB, batch conversion supported. Convert images to AVIF
Command line (ffmpeg / libavif)
For automation and batch processing, ffmpeg and avifenc (from libavif) are the most widely used tools. libavif is an open-source library for encoding and decoding AVIF images, and provides avifenc and avifdec as command-line tools.
Image editing software
Adobe Lightroom 7.0 and Lightroom Classic 13+ (October 2023) support AVIF export. GIMP 2.10+ and Photoshop (via plugins) also support AVIF. Support varies by version.
Server-side / CDN
CDNs such as Cloudflare (Polish feature) and Fastly can automatically serve AVIF to compatible browsers from JPEG or WebP originals. This avoids managing multiple file versions manually.
See real AVIF conversion results
The AVIF files on our samples page were generated by converting original JPEG and PNG source images with AVIF Tools. Each sample shows the original format, original file size, resulting AVIF file size, and the exact percentage reduction - so you can evaluate real compression results rather than relying on theoretical claims.
View AVIF Sample Files →Industry Adoption
AVIF is supported across all modern browsers and is used in production by major technology companies and image-delivery platforms.
- Netflix: Published AVIF compression tests in 2020, comparing AVIF against JPEG for thumbnail delivery.
- Browser vendors: Chrome (2020), Firefox (2021), Safari (2022) and Edge have all shipped native AVIF support.
- WordPress 6.5 (2024) added AVIF upload and media handling support.
- Adobe Lightroom 7.0 and Lightroom Classic 13 (October 2023) added HDR AVIF export.
History & Development
AVIF was developed by the Alliance for Open Media, a consortium formed in 2015 including Google, Mozilla, Netflix, Amazon, Microsoft, Apple, Meta, Intel, ARM, and NVIDIA, among others.
Alliance for Open Media founded with the goal of developing open, royalty-free media codecs.
AV1 video codec released (March 28), providing the intra-frame compression foundation for AVIF.
AVIF v1.0.0 specification finalized (February), officially introducing the format.
AVIF becomes standardized within the ISO/IEC 23000-22 MIAF framework (July). Chrome 85 adds AVIF support (August). Netflix publishes AVIF compression tests.
Firefox 93 adds static AVIF support (October).
Safari 16 adds AVIF support (September, macOS Ventura / iOS 16), completing static AVIF support across all major browsers. AVIF v1.1.0 released (April).
Safari 17 adds animated AVIF support (September, macOS Sonoma / iOS 17). Firefox 113 adds animated AVIF (May). AVIF reaches broad animated support across all major browsers.
Baseline 2024: January 26 marks AVIF's Baseline milestone - supported in all major browser engines for at least 12 months. WordPress 6.5 adds AVIF support.
AVIF v1.2.0 finalized (October 2025) - introduces Sample Transform Derived Image Items, enabling reconstruction of 16-bit or higher precision from combined image items. ISO/IEC 23000-22:2025 publishes the revised second edition of the MIAF standard.
Frequently Asked Questions
What is an AVIF file?
An AVIF file is an image stored in the AV1 Image File Format. It uses the AV1 video codec for compression and the HEIF container structure. AVIF files use the .avif extension and the MIME type image/avif.
Is AVIF better than JPEG?
AVIF can produce smaller files than JPEG at equivalent visual quality for many image types, based on independent tests including Netflix's 2020 study. However, results depend on the image, encoder, and quality settings. AVIF also encodes more slowly. The best way to evaluate is to test with your actual images - the AVIF Tools converter lets you do this for free.
Is AVIF better than WebP?
AVIF generally achieves better compression efficiency than WebP at equivalent quality, but at a higher encoding cost. WebP encodes faster and has slightly broader tool support. For most web use cases, both formats are good choices; AVIF may be preferable when maximising compression efficiency matters and encoding time is not a constraint.
Does AVIF support transparency?
Yes. AVIF supports full alpha channel transparency via a separately encoded alpha plane. It can be used instead of PNG for transparent graphics, often with substantially smaller file sizes. See our sample graphics for real measured results.
Does AVIF support animation?
Yes. AVIF supports image sequences (animated images). As of September 2023, animated AVIF is supported across all major browsers including Safari 17+, Chrome, Firefox, and Edge. For current compatibility data, see Can I Use - AVIF (animated).
Is AVIF lossless?
AVIF supports both lossy and lossless compression modes. Lossless AVIF preserves pixel-exact image data, but lossless AVIF files are typically larger than PNG for photographic content. Lossy mode is more commonly used for web delivery.
Do all browsers support AVIF?
All major browsers support static AVIF as of September 2022 (when Safari 16 was released). AVIF reached Baseline status in January 2024. For current global usage data, see Can I Use - AVIF.
How do I convert JPG or PNG to AVIF?
You can use the AVIF Tools converter to convert JPEG, PNG, WebP and HEIC files to AVIF online - no installation needed, files up to 30 MB, batch conversion supported. Static GIF files are also accepted; animated GIF conversion to animated AVIF is not currently supported. For command-line conversion, avifenc from libavif is a widely used AVIF encoding tool.
How do I convert AVIF back to JPEG or PNG?
AVIF Tools supports reverse conversion: AVIF to JPG and AVIF to PNG. This is useful when you need to share images with software or platforms that do not yet support AVIF.
Is AVIF royalty-free?
The Alliance for Open Media provides a royalty-free patent license to members and users under defined terms, with the goal of enabling AVIF use without per-unit licensing fees. The specification is published under the BSD 2-Clause License. Patent licensing in image codecs can be complex; for specific commercial or large-scale use, reviewing AOMedia's patent licensing policy directly is recommended.
Official Resources and Further Reading
- Alliance for Open Media - Official Website
- AVIF Specification v1.2.0 - AOMedia
- AVIF Specification - GitHub (AOMediaCodec)
- libavif - Reference AVIF encoder/decoder library
- Library of Congress - AVIF Format Description
- Netflix Technology Blog - AVIF for Next-Generation Image Coding (2020)
- Can I Use - AVIF Browser Support
- Can I Use - AVIF Animated (Sequence) Support
- Wikipedia - AVIF
- Smashing Magazine - Using Modern Image Formats: AVIF and WebP