Maximum Resolution of a Single AVIF Image

This article examines the maximum pixel resolution supported by a single AVIF (AV1 Image File Format) image item, covering both the absolute theoretical limits defined by the AV1 bitstream syntax and the practical limits enforced by AVIF compliance profiles. Readers will learn the precise dimensions possible for individual frames and how format constraints impact standard decoding.

The Absolute Bitstream Limit

At the specification level, a single AVIF image item consists of a single coded AV1 sequence frame. The AV1 bitstream architecture stores frame dimensions using 16-bit unsigned integers represented by max_frame_width_minus_1 and max_frame_height_minus_1.

Because a 16-bit integer ranges from 0 to 65,535, the maximum absolute pixel resolution supported by a single AV1 image item is:

• Maximum Width: 65,536 pixels
• Maximum Height: 65,536 pixels
• Maximum Total Area: 4,294,967,296 pixels (approximately 4.29 gigapixels)

Any single image item exceeding 65,536 pixels in either dimension cannot be represented within a standard AV1 frame header.

Limits Enforced by AVIF Compliance Profiles

While the syntax allows up to 65,536 × 65,536 pixels, AVIF defines compliance profiles to ensure hardware decoders can reliably open images. Standard decoders enforce operating level limits on single image items:

• Baseline Profile (Level 5.1): Restricts a single image item to a maximum total area of 8,912,896 pixels (approximately equivalent to a 4K image, such as 3840 × 2160), with a maximum width of 8,192 pixels and a maximum height of 4,352 pixels.
• Advanced Profile (Level 6.0): Restricts a single image item to a maximum total area of 35,651,584 pixels (approximately equivalent to an 8K image, such as 7680 × 4320), with a maximum width of 16,384 pixels and a maximum height of 8,704 pixels.

Single Items vs. Grid Collections

A single AVIF image item cannot exceed the 65,536 × 65,536 structural boundary, and standard profiles limit it further to 4K or 8K. To display ultra-high-resolution images that exceed profile constraints without breaking hardware decoders, AVIF uses an image grid (grid item type). An image grid splits a massive image into multiple smaller, compliant AV1 image items and tiles them back together, allowing multi-gigapixel canvases while keeping each individual image item within standard decoder limits.