ChromeOS Compatible - 3.5mm Headset Specification v2.0

Version: 2.0
Last updated: 2026-09-28

Overview

This document describes the requirements a ChromeOS Compatible wired headset meets. This specification is not for WWCB products, nor for a product designed and certified together with a Chromebook.

A single peripheral type specifies a subset of Audio modules that combine to make the spec for that peripheral. This mapping is provided in the Modular spec matrix.

The peripheral specification assembles using the text in this document specific to the peripheral, plus the relevant portions in each of the designated modules.

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.

Legend

Product Verb Development Action
"MUST" Mandatory product requirement
"SHOULD" Optional recommendation
"MAY" Nice to have

MINIMUM REQUIREMENTS

Generic peripheral Specifications

  • The peripheral MUST meet the minimum requirements defined in the Generic peripheral specifications.

3.5mm audio connector hardware specifications

MINIMUM REQUIREMENTS

Plug

  • 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

Buttons

  • 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

ADDITIONAL REQUIREMENTS

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

Buttons

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

Audio Quality

MINIMUM REQUIREMENTS

Capture Path - Mute

  • If there is any interface for users to mute the audio device, it MUST:
    • Maintain the mute state in a way that is not affected by:
      • Opening and closing the device.
      • Switching to another input device.

ADDITIONAL REQUIREMENTS

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

Playback Path - Loudness

  • [Mandatory] The device MUST comply with EN50332 standards.

Capture Path - Mute

  • [Mandatory] If there is any interface for users to mute the audio device, it MUST:
    • Mute the device such that all recorded samples are zeros or within the range of \((level_{max} - level_{min}) \le 0.0028 \text{ dBFS}\).
      • If the device cannot meet the requirements, then the device SHOULD have a button to mute.
      • The mute button on the device SHOULD trigger the system mute (mic).
      • The mute button SHOULD trigger the system mute (mic) through the Telephony, or the Consumer interface can be waived.
  • [Mandatory] If the user presses the mute button on the device or OS, the mute state MUST change.
  • [Mandatory] If the device synchronizes the MUTE state with the OS, then the mute state indicator (e.g., LED) on the device MUST change.

Capture Path - Output Frequency Response

  • [Mandatory] The device MUST be fully functional using the factory default frequency response and gain settings without any manual adjustment of the capture gain on OS.

  • [Mandatory] The following table specifies the computed average RMS dBFS level output under signal level 94 dBSPL.

    Device type Output level range versus sine tone frequency
    1 kHz 4 kHz 7 kHz
    Bluetooth and USB [-15, -5] dBFS 1kHz value ±5 dB 1kHz value ±5 dB
    3.5 mm wired [-23, 0] dBFS [-23, 0] dBFS [-23, 0] dBFS

Note: In Bluetooth and USB devices, the response around the 4 kHz and 7 kHz tones is given relative to the response at 1 kHz.

Audio Latency

MINIMUM REQUIREMENTS

  • None

ADDITIONAL REQUIREMENTS

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

Latency

  • [Mandatory] Output Latency: Audio playback MUST begin ≤ 500 ms after a user action that initiates playback.

Audio-Video (AV) Sync

  • [Mandatory] Accuracy: The audio playback latency report MUST be accurate to real world latency, i.e., ≤ 50 ms.

Works With Meet Certification

MINIMUM REQUIREMENTS

There is an existing Google Meet hardware peripheral qualification program covering part of this spec.

Peripherals qualified by the program are exempted from the following qualification items:

  • Playback Path - Loudness
  • Capture Path - Output Frequency Response

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 Use minimum and additional requirements format.
2024-06-17 1.3.1 ChromeOS Compatible spec derived. Initial Partner Site Publication.
2022-09-01 1.3 Related WWCB specification v1.3
2022-06-06 1.2 Related WWCB specification v1.2
2020-10-14 1.1 Related WWCB specification v1.1
2020-09-23 1.0 Related WWCB specification created.

  1. 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. ↩