ChromeOS Compatible - USB Audio Specification Module

Version: 2.0
Last updated: 2026-09-28

Overview

This specification module outlines the USB audio hardware and software requirements for audio peripherals.

Minimum and Additional Requirements

This specification document is divided into two sections:

  1. Minimum requirements describe the criteria for a peripheral category to be compatible.
  2. Additional requirements describe the criteria for certification.

Use these navigation buttons to show only the minimum or both the minimum and additional specification, respectively.

USB Audio Specifications

MINIMUM REQUIREMENTS

Hardware

Firmware
  • Peripheral MUST be declared as an audio device with a correct audio interface (0x01) descriptor.
    • There MUST be one corresponding descriptor for both input and output terminal.
      • It is recommended to report the USB Audio Class (UAC) terminal type:
  • If it has any button, it MUST be declared as an HID.

Software

Format

Refer to the Audio Format section.

HID Codes
  • For each HID event, it can only transmit one event at a time.
  • The correct event code and corresponding event code MUST be received when the button is pressed.
  • If there is any interface designed to provide peripheral functionalities, the USB peripheral MUST support emitting or receiving the corresponding HID events according to USB.org HID specification.
Jack Detection

  • If the USB device supports audio jack detection, it MUST declare support for USB Audio Class (UAC) in either of the following:

ADDITIONAL REQUIREMENTS

Along with the Minimum requirements, a peripheral MUST meet the following requirements to achieve certification:

  • None

Audio Format

MINIMUM REQUIREMENTS

Playback Recording
Sample rate ≥ 16 kHz ≥ 16 kHz
Format S16_LE S16_LE
  • The channel number and configuration MUST be correct.
  • All sampling rates the peripheral declares supported MUST work correctly.
    • The deviation between measured rate and sampling rate MUST be ≤ 0.1%.
    • The standard error for linear regression of measured rate MUST be < 30.

  • The device MUST support playback or capture under different sample rates it asserts to support. Otherwise, it requires the OS to add a specific configuration file to prevent it on the system side.

    For example: play audio under 44.1 kHz but capture voice under 48 kHz simultaneously.

ADDITIONAL REQUIREMENTS

Along with the Minimum requirements, a peripheral MUST meet the following requirements to achieve certification:

  • None

Revision history

Date Version Notes
2026-09-28 2.0 Update for ChromeOS Compatible specification.
2026-03-03 1.1.2 Change revision history format for use in macro.
2024-06-14 1.1.1 Minor text cleanup. Publish to partner site.
2023-06-07 1.1 Update UAC requirement.
2022-12-19 1.0 Initial version.