ChromeOS Compatible - Audio 3.5mm connector

Version: 2.0
Last updated: 2026-09-28

Overview

This specification module outlines the hardware requirements for 3.5mm audio connectors.

This specification document is divided into two sections:

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

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

Mechanical
- 4 conductor 3.5mm plug
- Pinout order
  - CTIA (LRGM) - Recommended
  - OMTP (LRMG) - Optional
Electrical
- Ear speaker impedance
  - ≥ 16 Ω
- Mic equivalent DC resistance
  - ≥ 1000 Ω

Only the following buttons are allowed:
- Play or Pause (Function A)
- Volume up (Function B)
- Volume down (Function C)
The control function equivalent Impedance* MUST satisfy the requirements in the following table:

Function Impedance¹ range

Play or Pause (Function A) [0, 70] Ω

Volume up (Function B) [210, 290] Ω

Volume down (Function C) [370, 680] Ω

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

[Mandatory] The audio device MUST NOT support the answer or hang up button, the OS does not support it.

Date	Version	Notes
2026-09-28	2.0	Update for ChromeOS Compatible specification.
2026-03-03	1.3.2	Change revision history format for use in macro.
2024-06-14	1.3.1	Use Ω for Ohms. Publish to partner site.
2024-05-10	1.3	Add Just Work requirement.
2023-04-24	1.2	Revise word usage.
2022-09-03	1.1	Add different requirement for 3.5mm Output Frequency Response.
2022-12-19	1.0	Initial version.

The equivalent impedance is measured from positive mic terminal to GND when button is pressed with 2.2 V mic bias applied through 2.2 kΩ resistor. ↩