There is no easy way to block adult websites on iPad, but there are methods and browser alternatives to help keep kids safe while on the tablet.
Steps
Method 1 of 2: Disable Safari and Use an Alternative Browser

Step 1. Click on the "Settings" icon on the iPad home screen to launch this application

Step 2. Click the General tab, then Restrictions

Step 3. Select “Enable Restrictions”

Step 4. Enter a four-digit password to enable or disable restrictions by clicking on the numbers on the screen
You will now be prompted to enter the password again to confirm it.

Step 5. Set the slider next to Safari to Off to disable the default iPad web browser
The Safari app will now be hidden on your device.

Step 6. Click on the App Store icon on your iPad home page and search for Safe Browser
Users have access to a number of browsers that allow blocking sites with obscene content and other specific resources. Available in both free and paid versions, Browser for Kids is a good option.
Method 2 of 2: Block Websites Through Your Computer

Step 1. Open www.opendns.com/home-solutions and click on the Get Started button below the Parental Controls feature

Step 2. Subscribe to the free OpenDNS Home service by clicking "OpenDNS Home" and clicking on the "Sign up now" button

Step 3. Enter your details and follow the instructions to block certain websites from loading on devices connected to your home network
Advice
You can access restricted applications such as Safari by returning to the Restrictions screen in the Settings app and entering your password
Warnings
- Limit the App Store app on your iPad to prevent children from installing the new browser without restrictions.
- Blocking websites from your computer using OpenDNS will not restrict website access when your iPad is using cellular data. It would be best to turn off cellular connectivity when kids are using your iPad.
- The restrictions applied to your home network will not work when iPad is connected to a different Wi-Fi network.