Version: v1.3.2  

Last updated: 2026-09-07

## Legend

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

## Requirements Scope

This specification document describes the criteria that ChromeOS Compatible USB
connectors meet. This specification should not be used for WWCB products, or a
product designed and certified together with a Chromebook.

## Connectors

- If the device supports USB transport, it MUST support one of the following:

  - **On-device USB-C receptacle**

    - The USB-C receptacle MUST comply with [Section 4.5.1.3.2 Sink
      Configuration Channel Functional Model](https://www.usb.org/sites/default/files/USB%20Type-C%20Spec%20R2.0%20-%20August%202019.pdf#page=155), and [Figure 4-9 Sink
      Functional Model for CC1 and CC2](https://www.usb.org/sites/default/files/USB%20Type-C%20Spec%20R2.0%20-%20August%202019.pdf#page=156).
    - USB-C receptacles on the device SHOULD NOT be recessed. The receptacle MUST NOT be altered in a way that prevents use of third party cables.
    - If a recessed receptacle is used, it SHOULD permit use of a USB-IF [dimensionally-compliant](https://www.usb.org/sites/default/files/USB%20Type-C%20Spec%20R2.0%20-%20August%202019.pdf#page=57) cable plug.
  - **Captive cable with USB-A plug**

    - MUST include a compliant USB Type-C to [USB 3.1 Standard-A
      Receptacle Adapter (USB Type-C Specification Section 3.6.1)](https://www.usb.org/sites/default/files/USB%20Type-C%20Spec%20R2.0%20-%20August%202019.pdf#page=85)
    - Proprietary wireless USB-A dongle is acceptable if an application in the Chrome Web Store allows pairing.
  - **Captive cable with USB-C plug**

    - USB-C captive cable design MUST use exactly one Rd pulldown as per USB-C specification section 3.4.3.
    - USB-C plug MUST comply with USB Type-C Specification [Section 4.5.2
      CC Functional and Behavioral Requirements](https://www.usb.org/sites/default/files/USB%20Type-C%20Spec%20R2.0%20-%20August%202019.pdf#page=161), specifically the rules around direct connect device or device with captive cable (These devices MUST apply and sense CC voltage levels on pin A5 only).
    - MUST NOT include a passive USB Type-C Receptacle to USB-A adapter, as these are forbidden by the USB Type-C Specification Section 2.2.
- If the product bundle includes a USB cable, the cable MUST be [USB-IF
  certified](https://www.usb.org/compliance)

- If the product bundle includes adapters, the adapter(s) MUST meet USB
  requirements.

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## Revision history

| Date | Version | Notes |
|---|---|---|
| 2026-09-07 | v1.3.2 | Formatting update. |
| 2026-03-05 | v1.3.1 | Initial publication on partner site. |
| 2024-05-16 | v1.3 | Latest internal draft. |
| 2022-04-11 | v0.1 | Doc created. |

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