Use built-in screen time or digital wellbeing settings
On iPhone, go to Settings > Screen Time > Content & Privacy Restrictions > Content Restrictions > Web Content > Limit Adult Websites > add websites to Never Allow
On Android, use Google Family Link to block websites for supervised accounts
Install a parental control app with website blocking features
Use a browser app with built-in site blocking or safe browsing controls
Set up DNS filtering with a service that blocks specific websites
Configure router-level website blocking for all devices on the network
Block websites through a mobile browser’s site settings or extension support
Use a firewall or security app that includes URL filtering
Remove or restrict browsers that do not support website blocking
Use app restrictions to prevent access to alternative browsers
Add blocked sites to the device’s restricted list whenever the feature is available