Quick Answer
HEIC is the best format for taking and storing photos on an iPhone: Apple's camera is optimized for it, and it saves storage space. AVIF is the best format for publishing images on the modern web, with excellent compression and broad browser support. A good workflow is to shoot in HEIC and convert to AVIF for the web.
HEIC vs AVIF Comparison
| Feature | HEIC | AVIF |
|---|---|---|
| Compression | HEVC-based, very efficient | AV1-based, most efficient available |
| File size | ~50% smaller than JPG | ~50-60% smaller than JPG |
| Browser support | Safari only | Chrome, Firefox, Edge, Safari 16.4+ |
| Transparency | Limited cross-platform | Yes (alpha channel) |
| Animation | No | Yes (native) |
| HDR support | Yes (Apple HDR) | Yes (wide gamut, 12-bit) |
| Encoding speed | Fast (hardware-accelerated on iPhone) | Slow (software encoding) |
| Use case | Photo capture and storage | Web image delivery |
| Specification | MPEG (proprietary licensing) | AOMedia (royalty-free) |
When to Use HEIC
- Taking photos on an iPhone, where it is the default format and the hardware is optimized for it
- Local storage on Apple devices, for the most quality per megabyte
- iCloud Photos, for efficient cloud storage and sync
- Live Photos, because HEIC keeps the motion and depth data
- Apple workflows such as AirDrop, iMessage, Pages and Keynote
When to Use AVIF
- Website images, where it gives the best compression for web delivery
- Progressive web apps that need a modern format with good performance
- HDR web content, thanks to wide gamut and high dynamic range support
- Animated web graphics, where it beats GIF on both quality and size
- Bandwidth-sensitive delivery, since it produces the smallest files
Key Differences Explained
The basic difference is capture versus delivery. HEIC was designed as a camera format: it suits the images smartphone cameras produce, and Apple devices encode it in hardware. AVIF was designed for the web, for efficient network transfer and broad browser compatibility. The two formats complement each other.
The licensing model affects long-term adoption. HEIC uses HEVC (H.265) compression, which has complex licensing requirements. AVIF uses AV1 compression, which is open and royalty-free. That has made AVIF more attractive for web standards and cross-platform use, while HEIC remains strong on Apple devices, where licensing is handled at the device level.
Encoding speed is very different. Modern iPhones and Macs encode HEIC in hardware, so it is nearly instant. AVIF encoding is computationally heavy and often takes seconds per image. HEIC therefore suits real-time capture, and AVIF is better suited to one-time conversion during a build or upload.
Try It Now
Convert HEIC to AVIF or other formats in your browser, with no software to install and no uploads to a server.