HEIC Format Guide

Available Conversions

About HEIC Format

HEIC (High Efficiency Image Container) is a modern image file format based on the HEIF (High Efficiency Image File Format) standard, which uses HEVC (High Efficiency Video Coding, also known as H.265) compression. Adopted by Apple as the default photo format for iOS 11, iPadOS 11, and macOS High Sierra in 2017, HEIC delivers approximately 50% smaller file sizes compared to JPEG while maintaining the same or better image quality. This dramatic improvement in compression efficiency allows iPhones and iPads to store twice as many photos in the same amount of storage space. HEIC supports advanced features including 16-bit color depth (compared to JPEG's 8-bit), transparency (alpha channel), multiple images in a single file (useful for Live Photos and burst sequences), image editing data, depth maps for Portrait mode, and EXIF metadata. The format can store both lossy and lossless compressed images, though lossy compression is most commonly used for photographs. Despite its technical advantages, HEIC faces significant compatibility challenges outside the Apple ecosystem, as many devices, operating systems, and applications still lack native support for the format, often requiring conversion to JPEG for sharing and viewing on non-Apple platforms.

History of HEIC

The HEIF (High Efficiency Image File Format) specification was developed by the Moving Picture Experts Group (MPEG) and standardized in 2015 as part of the MPEG-H Part 12 standard (ISO/IEC 23008-12). HEIF was designed to leverage the compression efficiency of HEVC/H.265, which was itself standardized in 2013 as a successor to H.264/AVC. While HEIF is the container format specification, HEIC specifically refers to images compressed with HEVC codec within the HEIF container. Apple played a significant role in HEIF's development through its membership in the MPEG working group and saw the format as a solution to the storage constraints of ever-increasing smartphone camera resolutions. At the 2017 Worldwide Developers Conference (WWDC), Apple announced that HEIC would become the default photo format in iOS 11 and macOS High Sierra, replacing JPEG for new photos captured on iPhones and iPads. The transition happened with the release of iOS 11 in September 2017, affecting hundreds of millions of devices almost overnight. Apple's implementation uses HEVC Main 10 profile with 10-bit color depth internally, though images are typically displayed as 8-bit for compatibility. The company also implemented intelligent compatibility features: when sharing photos via email or third-party apps, iOS can automatically convert HEIC to JPEG; when transferring to Windows PCs, users can choose to export as JPEG. However, these conversions created confusion among users who didn't understand why their photos were "sometimes HEIC, sometimes JPEG." Microsoft added HEIC support to Windows 10 in 2018 through a codec pack available from the Microsoft Store (initially paid, later free), though support remains inconsistent across Windows applications. Android gained limited HEIC support starting with Android 10 (2019), but most Android manufacturers continued using JPEG as the default capture format. Google Photos, Dropbox, and other cloud services added HEIC support to handle the influx of files from iOS devices. Despite being six years since Apple's adoption, HEIC remains largely an Apple-ecosystem format, with most of the world continuing to use JPEG for broad compatibility.

Key Features and Uses

HEIC achieves its superior compression through HEVC/H.265 encoding, which uses advanced compression techniques including larger coding tree units, improved motion compensation, and better entropy coding compared to JPEG's DCT-based compression. This results in approximately 50% file size reduction at equivalent quality, or significantly better quality at equivalent file sizes. The format supports 16-bit color depth, capturing and storing more color information than JPEG's 8-bit limitation, though this is often downsampled to 8-bit for display compatibility. HEIC includes native transparency support through an alpha channel, eliminating the need for separate PNG files for images requiring transparency. The format can store multiple images in a single file, which Apple uses for Live Photos (combining still image and video frames), burst photo sequences, and image sequences with editing data. HEIC supports non-destructive editing metadata, storing crop, rotation, and filter adjustments without modifying the original pixel data. The format can embed depth maps captured by dual-camera systems, preserving Portrait mode depth information for later refocusing or bokeh adjustments. HEIC supports wide color gamut (Display P3 and beyond), capturing and displaying more vibrant colors on compatible displays. The format includes support for image pyramids (multiple resolutions of the same image) and tiling for efficient handling of very large images. HEIC files contain comprehensive metadata including EXIF data, GPS coordinates, camera settings, and image editing history. Apple's implementation automatically handles conversion to JPEG when needed for compatibility, though this creates larger files and loses HEIC-specific features like transparency and depth maps.

Common Applications

HEIC is primarily used as the default photo format on Apple devices running iOS 11 or later and macOS High Sierra or later, meaning every photo captured on an iPhone or iPad since 2017 is stored as HEIC unless the user specifically changes settings to "Most Compatible" (JPEG) mode. The format stores hundreds of millions of photos daily across Apple's ecosystem, automatically syncing through iCloud Photos while preserving all HEIC features including Live Photo data and depth maps. Professional and amateur photographers using iPhones appreciate HEIC's storage efficiency, as it allows storing twice as many photos on device storage and in iCloud without quality compromise. The format is used for Live Photos on iOS, where the HEIC file contains both the still image and the brief video clip in a single container. Portrait mode photos on dual-camera iPhones store depth map data in HEIC format, enabling later adjustments to bokeh and focus. Screenshots on iOS and macOS are captured as HEIC by default, benefiting from smaller file sizes for the typically simple graphics. However, most users eventually convert their HEIC files to JPEG when sharing photos with non-Apple users, posting to websites that don't support HEIC, printing at photo services, or using third-party applications that lack HEIC support. This creates a common workflow where photos exist as HEIC on Apple devices for storage efficiency but are converted to JPEG for sharing and compatibility. Some professional photographers avoid HEIC entirely, shooting in RAW format or configuring their iPhones to capture JPEG to ensure compatibility with their existing workflows and software. Cloud storage services like Google Photos, Dropbox, OneDrive, and Amazon Photos support HEIC uploads and can display them, though they often convert to JPEG for web viewing. Social media platforms including Instagram, Facebook, and Twitter accept HEIC uploads but typically convert them to JPEG on their servers. The format sees limited use outside Apple devices, with few Android phones supporting HEIC capture despite the technical capability, largely due to patent licensing costs and compatibility concerns.

Advantages and Disadvantages