This wikiHow shows you how to change your application settings so that other users won't be able to see if you are online.
Steps
Method 1 of 2: iPhone and iPad

Step 1. Open the application

Step 2. Tap the Settings button
This is one of the options you can find at the bottom of the screen.

Step 3. Tap the Account button

Step 4. Select Privacy

Step 5. Tap the Status option

Step 6. Tap the Share with option only
..
- Do not select any contacts
- Your status will appear blank

Step 7. Tap the Done option
The phrase "0 contacts selected" should appear under "Share only with …"

Step 8. Tap the Privacy option

Step 9. Tap Last Accessed
This option allows you to check the contacts who can see the time of your last access on WhatsApp.

Step 10. Tap None
This removes the time indicating the last time you were online.
Method 2 of 2: Android

Step 1. Open WhatsApp

Step 2. Tap the Menu key
It is represented by the three vertical dots located in the upper right corner of the screen.

Step 3. Tap Settings

Step 4. Tap the Accounts option

Step 5. Tap Privacy

Step 6. Tap Status

Step 7. Tap the Share with option only
..
- Do not select any contacts
- Your status will appear blank

Step 8. Tap the white checkbox
It is located in a green circle in the lower right corner of the screen.
The phrase "0 contacts selected" should appear under "Status"

Step 9. Tap Last Accessed
This option allows you to check the contacts who can see the time of your last access on WhatsApp.

Step 10. Tap None
This removes the time indicating the last time you were online.