'adb' is not recognized as an internal or external command, operable program or batch file

On Window, sometimes I feel hard to click through many steps to find platform-tools and open Environment Variables Prompt, so the below steps maybe help

Step 1. Open cmd as Administrator

Step 2. File platform-tools path

cd C:\
dir /s adb.exe

Step 3: Edit Path in Edit Enviroment Variables Prompt

rundll32 sysdm.cpl,EditEnvironmentVariables

more, the command to open environment variables can not remember, so I often make an alias for it (eg: editenv), if you need to work with environment variables multiple time, you can use a permanent doskey to make alias

Step 4: Restart cmd

If your OS is Windows, then it is very simple. When you install Android Studio, adb.exe is located in the following folder:

C:\Users\**your-user-name**\AppData\Local\Android\Sdk\platform-tools

Copy the path and paste in your environment variables.

Open your terminal and type: adb it's done!

For environment variable, we have to need to follow some steps.

just open Android studio and press "Tools" on Top navigation bar

tools->SDK Manager

Where you can get SDK location

Open SDK folder -> platform-tools

You will need to set the PATH variable pointing to the directory where adb.exe is to be found. If you are using cmd.exe, this command will help:

set PATH=%PATH%;%USERPROFILE%\appdata\Local\Android\sdk\platform-tools

I recommand you using PowerShell

Set Android Studio Terminal to PowerShell:

Settings > Tools > Terminal > Shell path = pwsh.exe (instead of cmd.exe)

Open Terminal on Android Studio

PowerShell 7.0.1
Copyright (c) Microsoft Corporation. All rights reserved.

https://aka.ms/powershell
Type 'help' to get help.

PS >

Test the path for adb.exe

# `pikachu` should be replace your username
PS > test-path "C:\Users\pikachu\AppData\Local\Android\sdk\platform-tools"
True

Open your powershell profile file in your text editor

PS > notepad $profile

add below line, save and exit

# `pikachu` should be replaced with your username
$env:PATH+=";C:\Users\pikachu\AppData\Local\Android\sdk\platform-tools"

re-open Terminal and try adb

PS > adb
Android Debug Bridge version 1.0.41
Version 30.0.1-6435776
Installed as C:\Users\hdformat\AppData\Local\Android\sdk\platform-tools\adb.exe

global options:
 -a         listen on all network interfaces, not just localhost
 -d         use USB device (error if multiple devices connected)
 -e         use TCP/IP device (error if multiple TCP/IP devices available)
 -s SERIAL  use device with given serial (overrides $ANDROID_SERIAL)
 -t ID      use device with given transport id
 -H         name of adb server host [default=localhost]
 -P         port of adb server [default=5037]

Since I installed version 1.0.41,

I had to use the command "adb version" instead of "adb –version", in Windows 10.

Check and add these below loacations to the path variable:

C:\Users\Sameera\AppData\Local\Android\Sdk\tools
C:\Users\Sameera\AppData\Local\Android\Sdk\platform-tools
C:\Users\Sameera\AppData\Local\Android\Sdk\build-tools

ANDROID_HOME
C:\Users\Sameera\AppData\Local\Android\Sdk

In new version PowerShell, after all steps that mentioned before this, please attend:

before

adb

now

.\adb

This answer assumes that the PATH has been correctly set as described in the other answers

If you're on Windows 10 and dont have Admin rights then right click on the CMD, powershell ... program and select run as administrator. Then try adb [command]

If you didn't set a path for ADB, you can run .\adb instead of adb at sdk/platformtools.

It seems that Avast antivirus detects adb.exe as a virus and adds it to it chest

For those using macOS, this osxdaily.com article shows several ways to add adb to the $PATH.

Here's the one I prefer:

1. Add a file named adb to /etc/paths.d/ folder that just contains the path to adb's location: /Users/YourUserName/Library/Android/sdk/platform-tools/

   In a Terminal window, sudo vim /etc/paths.d/adb
   -> enter the path and save the file.

2. Close/re-open Terminal in order for it to see the change.