On Windows arm64 `os.machine()` returns `unknown`

[chris-addison]

Version

24.14.0

Platform

Microsoft Windows NT 10.0.26200.0 arm64

Subsystem

No response

What steps will reproduce the bug?

You can easily reproduce from command line:

node -e "console.log(os.machine())"

The returned value is unknown

How often does it reproduce? Is there a required condition?

This happens always on the Windows arm64 version of Node 24.14.0

What is the expected behavior? Why is that the expected behavior?

The os.machine() should return arm64 like it does on Mac Apple Silicon

What do you see instead?

os.machine() returns unknown

Additional information

This is on the native arm64 version of node. os.arch() correctly returns arm64

[chris-addison]

I wrote a quick powershell script to query various windows apis. Here's the json output:

{
  "node": {
    "platform": "win32",
    "arch": "arm64",
    "machine": "unknown",
    "release": "10.0.26200",
    "version": "Windows 11 Pro",
    "cpuModel": "Microsoft SQ3",
    "cpuCount": 8
  },
  "nativeApis": {
    "getSystemInfo": {
      "wProcessorArchitecture": 12,
      "processorArchitecture": "ARM64",
      "wReserved": 0,
      "dwPageSize": 4096,
      "lpMinimumApplicationAddress": "0x10000",
      "lpMaximumApplicationAddress": "0x7FFFFFFEFFFF",
      "dwActiveProcessorMask": "0xFF",
      "dwNumberOfProcessors": 8,
      "dwProcessorType": 0,
      "dwAllocationGranularity": 65536,
      "wProcessorLevel": 3403,
      "wProcessorRevision": 0
    },
    "getNativeSystemInfo": {
      "wProcessorArchitecture": 12,
      "processorArchitecture": "ARM64",
      "wReserved": 0,
      "dwPageSize": 4096,
      "dwNumberOfProcessors": 8,
      "dwProcessorType": 0,
      "dwAllocationGranularity": 65536,
      "wProcessorLevel": 3403,
      "wProcessorRevision": 0
    },
    "isWow64Process2": {
      "available": true,
      "processMachineCode": 0,
      "processMachine": "native",
      "nativeMachineCode": 43620,
      "nativeMachine": "ARM64"
    },
    "rtlGetVersion": {
      "ntstatus": 0,
      "major": 10,
      "minor": 0,
      "build": 26200,
      "platformId": 2,
      "servicePack": "",
      "servicePackMajor": 0,
      "servicePackMinor": 0
    },
    "getVersionExW": {
      "success": true,
      "lastError": 203,
      "major": 10,
      "minor": 0,
      "build": 26200,
      "platformId": 2,
      "servicePack": "",
      "servicePackMajor": 0,
      "servicePackMinor": 0
    },
    "environment": {
      "PROCESSOR_ARCHITECTURE": "ARM64",
      "PROCESSOR_IDENTIFIER": "ARMv8 (64-bit) Family 8 Model D4B Revision   0, Qualcomm Technologies Inc"
    }
  }
}

[zakiscoding]

Submitted a fix for this in PR #62235. The issue was that Windows ARM64 detection was falling back to 'unknown' in libuv. The fix uses Windows API GetSystemInfo() to properly detect ARM64 when os.machine() would otherwise return 'unknown'.

[Renegade334]

This is addressed by #61829.

[chaiphetwongchaiyatham0-ohmk]

Version

24.14.0

Platform

Microsoft Windows NT 10.0.26200.0 arm64

Subsystem

No response

What steps will reproduce the bug?

You can easily reproduce from command line:

node -e "console.log(os.machine())"

The returned value is unknown

How often does it reproduce? Is there a required condition?

This happens always on the Windows arm64 version of Node 24.14.0

What is the expected behavior? Why is that the expected behavior?

The os.machine() should return arm64 like it does on Mac Apple Silicon

What do you see instead?

os.machine() returns unknown

Additional information

This is on the native arm64 version of node. os.arch() correctly returns arm64

[khalidsaidi]

A2ABench has an accepted answer for this imported thread.

• Thread: https://a2abench-api.web.app/q/cmmo05vxx0055b4x5ut9faihb
• Accepted at: 2026-03-25T18:34:59.517Z
• Accepted answer agent: ai village
• Answer preview: "No matching threads were found for this query."