HEIC to AVIF: Complete Conversion Guide for Web & Mobile

By Bill Crawford  ·  March 2026  ·  9 min read  ·  Last updated March 5, 2026

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What Is AVIF?

AVIF (AV1 Image File Format) is a modern still-image format derived from the AV1 video codec, developed by the Alliance for Open Media — a consortium including Google, Apple, Netflix, Microsoft, and Mozilla. Unlike HEIC (which uses the proprietary HEVC/H.265 codec), AVIF is fully open-source and royalty-free.

AVIF was finalized in 2019 and has since become the highest-efficiency image format broadly supported by major browsers. On a practical level it means your HEIC photos from an iPhone can become web-ready files that are dramatically smaller than JPG — with no visible quality difference.

HEIC vs AVIF: How They Compare

Both HEIC and AVIF are efficient compressed formats, but they differ significantly in openness, browser support, and web suitability.

The practical takeaway: HEIC is excellent for keeping photos on your iPhone. AVIF is the right choice for publishing those photos on the web, distributing via a CDN, or building apps that serve images efficiently.

AVIF vs JPG and WebP: The Numbers

Compression efficiency is where AVIF really shines. Across independent benchmarks, AVIF consistently outperforms both JPG and WebP:

• AVIF is typically 50% smaller than JPG at equal visual quality (SSIM)
• AVIF is typically 20–30% smaller than WebP at the same visual quality
• At very low bitrates (aggressive compression), AVIF degrades more gracefully — avoiding the blocky artifacts JPG is known for

For a web page with 20 product images that are currently JPGs at 200 KB each (4 MB total), converting to AVIF could reduce that to under 2 MB — directly improving page load time and Core Web Vitals.

When Should You Convert HEIC to AVIF?

AVIF is the right choice when:

• Publishing to a website or web app — serve AVIF to modern browsers, WebP/JPG fallback for legacy
• Uploading to a CDN — most major CDNs (Cloudflare, Fastly, ImageKit) now support AVIF delivery natively
• Sending photos via modern messaging apps — many accept AVIF and display it natively
• Storage optimization — AVIF archives take significantly less space than JPG with comparable quality
• E-commerce product images — faster-loading pages with smaller images improve conversion rates

AVIF is not the right choice when you need universal compatibility (e.g. emailing to someone with an older device) or when pixel-perfect lossless output is required (use TIFF instead).

When Not to Use AVIF

• Need lossless quality — use HEIC to TIFF for pixel-perfect archiving
• Universal file sharing — use HEIC to JPG for maximum compatibility across all devices and apps
• Legacy browser support required — IE11, older Chrome/Firefox/Safari users cannot render AVIF
• Print workflows — print shops expect TIFF or high-quality JPG, not AVIF

AVIF Browser Support in 2026

As of 2026, AVIF decode (viewing) is supported in:

• Chrome 85+ (August 2020) — full support
• Edge 85+ — full support (same engine as Chrome)
• Firefox 93+ (October 2021) — full support
• Safari 16.4+ (March 2023) — decode support; encoding via Canvas API is browser-dependent
• iOS Safari 16.4+ — supported on devices running iOS 16.4 or later

For encoding (creating AVIF files in the browser, as this tool does), Chrome and Edge are the most reliable. Safari added decode support in 2023 but canvas.toBlob('image/avif') behavior varies — use Chrome or Edge for guaranteed output.

Serving AVIF on the Web: Best Practices

The recommended pattern for serving AVIF with fallback is the HTML <picture> element:

<picture>
  <source srcset="photo.avif" type="image/avif">
  <source srcset="photo.webp" type="image/webp">
  <img src="photo.jpg" alt="Description" width="800" height="600">
</picture>

Browsers that support AVIF use the first source. Browsers that support WebP use the second. Everything else falls back to the JPG. You only need to provide the format your users' browsers support — the browser picks automatically.

For CDN-based image optimization (Cloudflare Images, Imgix, Fastly), many platforms handle AVIF conversion and serving automatically based on the Accept header sent by the browser.

AVIF vs TIFF: Choosing the Right Format

If you're unsure whether to use AVIF or TIFF for your HEIC photos, the answer depends entirely on your workflow:

• Editing / archiving / print — use TIFF. It is lossless, preserves every pixel, and is the standard for professional print and archival workflows. See HEIC to TIFF: Complete Conversion Guide.
• Web / app delivery / storage efficiency — use AVIF. It delivers better visual quality per byte than any other widely supported format.

Many professional workflows use both: convert to TIFF for the master archive, then generate AVIF (and WebP/JPG) for web delivery from the TIFF master.

Understanding AVIF Quality Settings

This tool converts at quality 0.85 (on a 0–1 scale, where 1 is maximum quality). At this setting:

• Visual quality is excellent — virtually indistinguishable from the original HEIC
• File sizes are typically 60–75% smaller than JPG at equivalent visual quality
• Files are 20–35% smaller than equivalent WebP

For web use, quality 0.80–0.90 is the practical sweet spot. Below 0.70, AVIF can produce visible artifacts (though still more graceful than JPG artifacts). Above 0.95, file sizes increase significantly with minimal visible benefit.

Privacy: Why Browser-Based Conversion Matters

This tool performs all conversion inside your browser — no HEIC file is ever uploaded to a server. This matters for personal photos, client work, medical images, or any situation where you don't want a third party to have access to your files. The JavaScript libraries (heic2any for HEIC decoding, the browser's native Canvas API for AVIF encoding) run entirely in your browser's sandbox.

Frequently Asked Questions

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