Whether you want to use it on Android, iPhone or your computer, it is very easy to download WhatsApp.
Steps
Method 1 of 3: Install on Android

Step 1. Open the Play Store
It's the app with a white icon and a multicolored triangle in it. You will find it with the rest of the applications.

Step 2. Tap on the magnifying glass
It is located at the top right of the screen.

Step 3. Type whatsapp in the search bar
Then tap on Search. This will allow you to find WhatsApp in the Play Store, it should be the first app in the results.

Step 4. Click on the application icon
This should take you back to the setup page.

Step 5. Click Install
You should see it at the top right of the screen.

Step 6. Click I Agree
You will see it at the bottom of the window that appeared. This should start downloading the app.

Step 7. Wait for the download to complete
Then open the app. It is located on the right side of the screen. Now that you have it installed, you need to configure it.

Step 8. Tap I agree
The button is located at the bottom of the screen.

Step 9. Enter your phone number
You'll enter it in the text box in the middle of the page.

Step 10. Tap OK when it appears
WhatsApp will send you a message with a verification code to the number you entered.
If you can't receive text messages on your phone, choose the phone call instead to listen to an automatic recording that will give you your code.

Step 11. Open the text message inbox
You will see a new message there.

Step 12. Tap on the message
There you should read: "Your WhatsApp code is (six digits)", but you can also just tap on the link in the message to verify your device.

Step 13. Enter the six-digit code
As long as you are correct, you will verify that you are the owner of the phone and return to the account creation page.

Step 14. Enter your name and put a photo
There's no need to add a photo, but it might help your contacts identify you (especially if you're using a different name).
- If you have downloaded WhatsApp in the past, you will be able to find your old conversations.
- You can also tap Use my Facebook information to use the name and profile picture that appear on your Facebook account.

Step 15. Tap Next
The button is located at the top right. The application is now installed and configured, you can start using WhatsApp.
Method 2 of 3: Install on iPhone

Step 1. Open the App Store
It's a light blue icon with an A on it. You will probably see it on the home screen.

Step 2. Click Search
This button that looks like a magnifying glass is at the bottom of the screen.

Step 3. Click on the search bar
You'll find it at the top of the screen.

Step 4. Type whatsapp in the bar and click search
It's a button at the bottom right of the screen.

Step 5. Click Get on the right of the app
The WhatsApp icon looks like a green bubble around a white phone handset.
If you had already downloaded the app, the icon will look like a gray cloud with an arrow pointing down. Click on it and you will open WhatsApp.

Step 6. Click Install once it appears
This button is in the same place as the previous Get.

Step 7. Train your Apple password
If you recently signed into the App Store with your ID, you will not be prompted for it.
You can also use Touch ID if your phone supports it

Step 8. Wait for the download to finish
Tap on Open. The button is on the right. This allows you to open the app and start adjusting the settings.

Step 9. Tap OK
Tap ens on Do not allow to block popups. These windows will ask you if you want to let WhatsApp have access to your contacts and send you notifications.

Step 10. Tap I agree
It's at the bottom of the screen.

Step 11. Enter your phone number
Then tap on Finish. Your phone number will appear in the text field in the middle of the screen and Ended top right.

Step 12. Tap Yes
WhatsApp will send you a confirmation code in your messages.
If you do not have a number that allows you to receive texts, select the option to be called instead and you will receive a call recorded with your code number.

Step 13. Open your messages
It is the application in green with a white bubble.

Step 14. Open the message that comes from WhatsApp
It should display something like: "your Whatsapp code is (six digits)".

Step 15. Enter the six-digit code in WhatsApp
As long as you enter it correctly, the app will let you finish adjusting your settings.

Step 16. Enter your name
Type it in the text box where it says "Your name" in the middle of the screen.
- You can also add a profile picture.
- You might also see the “Restore” option at the top right of the screen which allows you to find your old conversations. This will only work if you have used WhatsApp on this phone before.

Step 17. Tap Finish
The app is now installed and set up on your phone, which means you are ready to use WhatsApp!
Method 3 of 3: Install on the computer

Step 1. Go to the WhatsApp site
It can be found at the following address: https://www.whatsapp.com/. You can download the desktop version of the application there.
You are going to need to have WhatsApp installed on your phone to be able to connect to the application on the computer.

Step 2. Click Mac or Windows
The option is near the bottom of the page.

Step 3. Click the green Download button
It is on the right of the page. Clicking on it will start the download, but you may need to choose a location for it first.
Depending on the computer you have, this button might read "Download for Windows 64-Bit" or "Download for Maximum OS X".

Step 4. Wait for the download to complete
Double click on the file. It will probably be in the folder where downloads are saved by default.

Step 5. Wait for the installation to complete
When finished, you should see the WhatsApp icon, a white phone on a green background, appear on the desktop.
During installation, a white window with a green illustration should appear

Step 6. Double click the icon if WhatsApp is not open
This will launch the login page where you will see a QR code (a sort of checkerboard with messy black and white squares).

Step 7. Open WhatsApp on the phone
If you haven't installed it, you need to do it now on your iPhone or Android phone before continuing.

Step 8. Open the WhatsApp scanner
Depending on your phone, the path to open it will be as follows.
- On iPhone: tap Settings in the lower right corner of the screen, then click WhatsApp for the web near the top of the screen.
- On Android: tap ⋮, then on WhatsApp for the web at the top of the menu.

Step 9. Point the camera at the QR code
After a short while, WhatsApp will scan the code and it will give your computer permission to log into your account. You can now use the application directly from your computer!
- If the QR code has expired, you must refresh the page by clicking on the appropriate button.
- If the scanner does not work, you need to make sure that the entire QR code appears on your phone, you may have to move your phone back a bit to scan the entire code.