HEIC vs AVIF: Comparing Image Formats

AVIF (AV1 Image Format) is a newer image format developed by the Alliance for Open Media, built on the AV1 video codec. It was designed to address the limitations of older formats by providing significantly better compression efficiency and support for advanced features like HDR (High Dynamic Range) and wider color spaces. While AVIF is technically superior in many ways, HEIC has dominated on Apple devices since iOS 11 due to its native support and integration with the iPhone ecosystem.

The key difference is that AVIF uses modern compression algorithms that can represent the same image quality with much smaller file sizes, sometimes 50-80% smaller than HEIC.

AVIF achieves dramatically better compression ratios than HEIC. For the same image quality, AVIF files are typically 30-50% smaller, and in some cases up to 80% smaller. This is because AVIF uses advanced entropy coding and prediction techniques developed for the AV1 video standard. HEIC uses HEVC (High Efficiency Video Coding) compression, which is already efficient but not as advanced as AV1.

For example, a 5MB HEIC photo might compress to 1-2MB in AVIF format at identical visual quality. This size reduction is especially valuable for mobile users where bandwidth and storage matter, and for websites where reducing page load time improves user experience and SEO performance.

However, file size reduction isn't everything - the time required to encode AVIF is significantly longer than HEIC, which can impact your workflow if you're processing hundreds of images.

Both HEIC and AVIF support HDR (High Dynamic Range) images natively. HDR allows photos to contain a much wider range of brightness values, from deep shadows to bright highlights with detail in both, matching what the human eye can perceive. HEIC was the first format to bring HDR to iPhone photos, while AVIF offers similar capabilities with potentially better compression.

AVIF also supports a much wider color gamut (beyond sRGB), 12-bit color depth (vs HEIC's 10-bit), and lossless compression option. These features make AVIF ideal for professional photography, digital art, and high-end visual content where color accuracy and detail matter most.

HEIC, by contrast, is limited to 10-bit color depth and standard dynamic range in most implementations. For everyday photos and web content, these differences rarely matter, which is why HEIC remains perfectly adequate for most use cases.

HEIC has near-universal support on Apple devices (iPhone, iPad, Mac) but limited support elsewhere. Windows requires the HEVC Video Extensions codec, and many upload forms, older Android devices, and legacy applications reject HEIC files. This is HEIC's greatest disadvantage. AVIF support, while improving rapidly, is still incomplete. Modern browsers (Chrome 85+, Firefox 93+, Safari 16+, Edge 85+) support AVIF, but older browsers do not.

This creates a practical challenge: both formats are not yet suitable as the primary format for websites with diverse audiences, as you would need to serve fallbacks to older browsers. However, this is changing quickly as browser support expands and older versions fade from use.

Mobile support varies by device and operating system. Apple's devices gained AVIF support in iOS 16+, while Android devices have better support in recent versions. If your audience includes users on older devices or browsers, you will need to provide a fallback format like JPEG.

Use HEIC when: you are working within the Apple ecosystem (iPhone, iPad, Mac) and need native support, when you want to preserve Live Photos and depth data, when you need 10-bit color and HDR from iPhone photos, or when simplicity and instant broad support on Apple devices are priorities. HEIC compression is also straightforward to implement on Apple devices.

Use AVIF when: you are targeting modern browsers and devices only, when file size reduction significantly impacts your project (e.g., streaming services, mobile apps, high-traffic sites), when you need HDR or advanced color features, or when you can provide proper browser fallbacks. AVIF is ideal for professional portfolios, digital galleries, and mobile-first applications.

Many professionals use both formats strategically: serve AVIF as the primary format with HEIC as a fallback for Apple devices, leveraging the HTML <picture> element to serve AVIF to capable browsers and HEIC to others.

Converting HEIC images to AVIF is straightforward with heic.now's HEIC to AVIF converter. Simply upload your HEIC file, and the tool will convert it to AVIF format while preserving quality. You can adjust compression settings to balance file size against visual quality according to your needs.

For batch conversions of multiple images, heic.now supports uploading multiple files at once, which saves significant time compared to converting files individually. This is especially useful if you are migrating an entire image library to the AVIF format.

Keep in mind that AVIF encoding takes longer than HEIC due to its more sophisticated compression algorithms. A single image typically takes a few seconds, but patience pays off in the file size savings you will achieve.

AVIF is not the only modern image format worth considering. WebP is another newer format that offers better compression than JPEG with better browser support than AVIF, making it a good middle ground. WebP supports some advanced features but not HDR, and browser support is more mature than AVIF.

The format landscape continues to evolve, and choosing between HEIC, AVIF, and WebP depends on your specific requirements for compatibility, features, and file size. For most web applications, a strategy of serving WebP to compatible browsers with JPEG fallbacks remains practical today, with a future migration to AVIF as browser support becomes near-universal.