What is AVIF? The AV1-based image format, royalty-free, and the future of web images

The one-sentence answer

AVIF is the AV1 Image File Format — a single-frame image wrapped in the HEIF container and compressed with the AV1 video codec. It ships smaller files than HEIC or WebP at matched visual quality, it's royalty-free, and it's supported by every major browser as of 2022.

Who made it and why

AVIF was standardised by the Alliance for Open Media(AOMedia) in 2019. The membership roster is unusual — Google, Netflix, Mozilla, Microsoft, Apple, Amazon, Intel, Nvidia, Meta, and a dozen more. It's the closest thing the internet has to a "whole industry agrees" image format.

The reason they unified: HEIC proved modern video codecs make great still-image codecs, but HEVC is patent-encumbered and Apple pays MPEG-LA to use it. The rest of the industry — YouTube, Netflix, Firefox, Chrome — wasn't willing to license HEVC at scale. AOMedia's answer was AV1: a next-generation video codec designed to be royalty-free, measurably better than HEVC, with an explicit still-image profile called AVIF.

Think of it as the same engineering trick as HEIC (HEIF container + video codec for stills), but with an unencumbered codec and a broader political coalition. That's why you see AVIF on Netflix, Google Image Search, Cloudflare, Shopify — and not so much inside Apple's first-party apps, where HEIC still wins.

AVIF vs JPG — the size chart

Same 12-megapixel photograph, matched perceptual quality (SSIM ≈ 0.96) across four formats. AVIF is the smallest; JPG, the oldest format in the chart, is the largest by a wide margin.

AVIF at SSIM ≈ 0.96 lands roughly 40–50% smaller than JPG Q85 on natural photography, 20–30% smaller than WebP, and comfortably smaller than HEIC on the same content. At very aggressive quality settings (SSIM ≈ 0.93, visibly lossy) AVIF keeps looking better than the others because its tools — directional intra-prediction, larger block sizes, chroma-from-luma — handle low-bitrate scenarios well. On tiny thumbnails (<100 KB target) the gap widens further.

AVIF's real trade-offs

AVIF is not pure upside. The honest version:

Slow encode

AV1 was designed for 1% better compression at any cost, and the cost shows up in encoder time. Encoding a 12-MP photo:

• JPG: <50 ms.
• WebP: 150–250 ms.
• HEIC: 300–600 ms (hardware-accelerated on Apple Silicon).
• AVIF at "speed 6" (reasonable default): 2–6 seconds on a modern laptop.
• AVIF at "speed 0" (best compression): tens of seconds per frame.

That's fine for server-side pipelines and CDN-origin conversion (where you encode once, serve millions of times) but painful for interactive tools processing hundreds of images per session. Our encoder defaults to speed 6 as the right balance and exposes a "slow/best compression" toggle for users who want the last few kilobytes.

Decode is actually fast

Encoding is slow, decoding is not. AV1 decode on any modern CPU happens in a few milliseconds per frame; the codec has hardware decode support on most 2021+ chipsets (Intel 11th-gen+, Apple M1+, recent AMD Ryzen, Snapdragon 8 Gen 1+). The bottleneck is one-way — encoder CPU cost, not user-visible load time.

Tooling maturity

AVIF shipped to Chrome in 2020, Firefox in 2021, Safari in 2022 — historically recent. Desktop editing apps caught up later: Photoshop gained AVIF in 2023 (after years of plugin-only support), GIMP in 2.10+, Affinity in 2024. Print pipelines and Microsoft Office still treat AVIF as exotic. That's the main reason you end up needing to convert AVIF back to JPG.

Browser + OS support in 2026

AVIF's browser support is, as of 2026, effectively universal:

AVIF vs WebP — the question everyone asks

If you're choosing between AVIF and WebP for a web project:

• File size: AVIF wins. Expect 20–30% smaller files at matched quality.
• Encode time: WebP wins. 10–30× faster to encode.
• Browser coverage: identical in 2026 (both universal).
• Animation: WebP has more mature animated support; animated AVIF works but tooling is newer.
• Colour / HDR: AVIF wins. 10-bit and 12-bit profiles, HDR10 metadata, wide-gamut colour primaries — all spec-level features.
• Transparency: tied — both support alpha, both work well.
• Decode performance: roughly tied on modern hardware; AVIF edges when hardware AV1 decode is available.

The practical answer for most sites: serve AVIF first, fall back to WebP, fall back to JPG. The HTML <picture>element handles the negotiation. Encode AVIF once (slow), serve forever (cheap). WebP still wins on encode speed, so for user-generated-content pipelines where you're re-encoding on every upload, WebP can be the better pick until AV1 hardware encoders become ubiquitous.

AVIF vs HEIC — close cousins, different politics

• Codec: AV1 vs HEVC. AV1 is newer and ~20% more efficient at matched quality.
• Licensing: AVIF is royalty-free by AOMedia charter. HEIC is patent-encumbered (MPEG-LA).
• Ecosystem: AVIF dominates the web. HEIC dominates Apple devices.
• Hardware acceleration: both have it on current silicon. AV1 hardware decode is universal; hardware encode is newer and limited to recent chipsets.
• Feature parity: both support 10-bit, 12-bit, HDR, wide-gamut, transparency, animation.

Same container family (HEIF), different codec, different political alignment. A useful mental model: HEIC is the format you get from the camera (Apple-side); AVIF is the format that camera picture ends up as after it's been through a CDN.

When to convert AVIF (and to what)

Situations where you realistically need to convert out of AVIF:

• You downloaded an AVIF from the web and need to print it. Most print shops want JPG or TIFF. AVIF to JPG at Q90 for near-lossless print quality.
• You need to edit in software that doesn't support AVIF yet — legacy Photoshop, older Affinity, enterprise-locked editors. Convert to PNG for lossless editing, or JPG if size matters more than fidelity.
• Embedding in a document for a mixed audience — Word, PowerPoint, or a PDF going to people on older software. JPG is safer.
• Sending via email to a broad list. Outlook desktop still treats AVIF as exotic. JPG delivers reliably.
• Uploading to a site with a strict allow-list (job portals, government forms, legacy CMS).

Converting AVIF to JPG is visually lossless at high quality settings — you're moving from one lossy codec to another, but both have plenty of headroom at Q90+. The file will be larger than the AVIF (JPG can't match AVIF's efficiency) but that's the price of universal compatibility.

When to convert TO AVIF

• You run a website and already serve WebP. Layering AVIF on top with a <picture> fallback saves another 20–30% for users on modern browsers (most of them in 2026).
• You're archiving a photo library and want the smallest possible long-term storage. AVIF lossless is ~40% smaller than PNG; AVIF lossy at visually-imperceptible settings is ~5% of the original RAW size.
• You need wide-gamut / HDR preservation for a colour-managed workflow; AVIF is the cleanest non-Apple format for this.

Don't convert to AVIF when: the recipient is on software older than 2023; you're printing; you're embedding in a document bound for corporate Office; you need fast encoding in an interactive pipeline. In those cases WebP or JPG remains the right target.

How we handle AVIF

Our decoder is a WebAssembly build of libavif — the reference implementation from AOMedia, with an AV1 decoder baked in. That runs entirely in your browser tab: no upload, no server processing, no copy of the image touching our disk. The decoder respects ICC profiles (colour stays accurate on wide-gamut monitors), surfaces the 10-bit / 12-bit bit-depth honestly, and preserves the alpha channel when converting to PNG.

On the encode side we ship libaom at speed 6 by default (fast enough for interactive use, close to the compression ceiling) with a slow/best-compression toggle in advanced settings for users who want the final kilobyte squeezed out. Batches run in a web worker so the UI stays responsive; we hand back a ZIP for multi-file jobs.

Frequently asked questions

What does AVIF stand for?

AV1 Image File Format. It's a still-image profile of the AV1 video codec, packaged in the HEIF container (ISO/IEC 23008-12) and standardised by the Alliance for Open Media in 2019.

Is AVIF better than WebP?

For file size and image quality at matched SSIM, yes: AVIF is consistently 20–30% smaller. For encode speed, tooling maturity, and animation support, WebP still edges ahead. On a website serving static images, use both: AVIF first with WebP fallback in a<picture> tag.

Why can't I open AVIF in my editor?

Almost certainly because your editor is >2 years old. Photoshop, GIMP, Affinity, Krita all added first-class AVIF support between 2023 and 2024. If you can't update, convert to PNG or JPG first — lossless round-trip for PNG, visually-lossless for JPG Q90.

Does AVIF support transparency?

Yes. Full 8-bit or higher alpha channel in both lossy and lossless modes. Converting a transparent AVIF to JPG flattens the alpha (JPG has none); converting to PNG preserves it exactly.

Is AVIF lossless?

It can be — AVIF has an explicit lossless mode and a lossy mode. Same .avif extension, different compression setting at encode time. Our converter exposes both. Lossless AVIF is typically 30–50% smaller than PNG with bit-exact pixel preservation.

Why is AVIF encoding so slow?

AV1 was designed to prioritise compression efficiency over encode speed — the codec has many more decision paths than HEVC or VP9, and searching them exhaustively takes time. Fast encoders (speed 8+) are close to WebP speed but give up some compression; slow encoders (speed 0–2) hit the efficiency ceiling but take tens of seconds per frame. We default to speed 6 as the best compromise.

What's the maximum image size for AVIF?

65,536 × 65,536 pixels in theory — far higher than JPG or WebP can handle. In practice memory is the real limit; decoding a 30,000 × 30,000 AVIF uses several gigabytes of RAM. For everyday photos and web images this is a non-issue.

Ready?

Got an AVIF you need to convert? Use AVIF to JPG for universal compatibility or AVIF to PNG for lossless editing. Want to shrink your own images for the web? Pair JPG to WebP with an AVIF-serving CDN and you've covered 99% of visitors at minimum file size. For the wider format landscape see what HEIC is and what WebP is — together they explain where every image format on the modern web came from.