Skip to content
Go to file


Failed to load latest commit information.
Latest commit message
Commit time

machineid provides support for reading the unique machine id of most host OS's (without admin privileges)

Image of Gopher 47

… because sometimes you just need to reliably identify your machines.

GoDoc Go Report Card

Main Features

  • Cross-Platform (tested on Win7+, Debian 8+, Ubuntu 14.04+, OS X 10.6+, FreeBSD 11+)
  • No admin privileges required
  • Hardware independent (no usage of MAC, BIOS or CPU — those are too unreliable, especially in a VM environment)
  • IDs are unique1 to the installed OS


Get the library with

go get

You can also add the cli app directly to your $GOPATH/bin with

go get


package main

import (

func main() {
  id, err := machineid.ID()
  if err != nil {

Or even better, use securely hashed machine IDs:

package main

import (

func main() {
  id, err := machineid.ProtectedID("myAppName")
  if err != nil {

Function: ID() (string, error)

Returns original machine id as a string.

Function: ProtectedID(appID string) (string, error)

Returns hashed version of the machine ID as a string. The hash is generated in a cryptographically secure way, using a fixed, application-specific key (calculates HMAC-SHA256 of the app ID, keyed by the machine ID).

What you get

This package returns the OS native machine UUID/GUID, which the OS uses for internal needs.

All machine IDs are usually generated during system installation and stay constant for all subsequent boots.

The following sources are used:

  • BSD uses /etc/hostid and smbios.system.uuid as a fallback
  • Linux uses /var/lib/dbus/machine-id (man)
  • OS X uses IOPlatformUUID
  • Windows uses the MachineGuid from HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Cryptography

Unique Key Reliability

Do note, that machine-id and MachineGuid can be changed by root/admin, although that may not come without cost (broken system services and more). Most IDs won't be regenerated by the OS, when you clone/image/restore a particular OS installation. This is a well known issue with cloned windows installs (not using the official sysprep tools).

Linux users can generate a new id with dbus-uuidgen and put the id into /var/lib/dbus/machine-id and /etc/machine-id. Windows users can use the sysprep toolchain to create images, which produce valid images ready for distribution. Such images produce a new unique machine ID on each deployment.

Security Considerations

A machine ID uniquely identifies the host. Therefore it should be considered "confidential", and must not be exposed in untrusted environments. If you need a stable unique identifier for your app, do not use the machine ID directly.

A reliable solution is to hash the machine ID in a cryptographically secure way, using a fixed, application-specific key.

That way the ID will be properly unique, and derived in a constant way from the machine ID but there will be no way to retrieve the original machine ID from the application-specific one.

Do something along these lines:

package main

import (

const appKey = "WowSuchNiceApp"

func main() {
  id, _ := machineid.ID()
  fmt.Println(protect(appKey, id))
  // Output: dbabdb7baa54845f9bec96e2e8a87be2d01794c66fdebac3df7edd857f3d9f97

func protect(appID, id string) string {
  mac := hmac.New(sha256.New, []byte(id))
  return fmt.Sprintf("%x", mac.Sum(nil))

Or simply use the convenience API call:

hashedID, err := machineid.ProtectedID("myAppName")


Don't want to download code, and just need a way to get the data by yourself?


cat /etc/hostid
# or (might be empty)
kenv -q smbios.system.uuid


cat /var/lib/dbus/machine-id
# or when not found (e.g. Fedora 20)
cat /etc/machine-id


ioreg -rd1 -c IOPlatformExpertDevice | grep IOPlatformUUID


reg query HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Cryptography /v MachineGuid


  • Open Windows Registry via regedit
  • Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Cryptography
  • Take value of key MachineGuid


The Go gopher was created by Denis Brodbeck with, based on original artwork from Renee French.


The MIT License (MIT) — Denis Brodbeck. Please have a look at the for more details.

You can’t perform that action at this time.