If you want to add networks to MetaMask, Chainlist will be a great way for both Extension and Mobile.
For Extension
1. Head to the Chainlist site at chainlist.wtf
2. Connect your wallet to the site through ‘Connect wallet’ button on top right
When successful, your wallet address will replace the ‘Connect wallet’ button
3. Use the search bar to find the network you want to connect. Once you’ve found it, click the button ‘Add Chain’
4. MetaMask itself will now spring into action, and will present you with an approval menu. Click ‘Approve’ button to proceed
5. This will be followed by a menu asking you whether you want to switch to the new network immediately. Confirm or reject this depending on your needs; either way, the new network will be added.
For Mobile
1. Head to the Chainlist site. To do so, tap the hamburger icon in the top left of the app and find ‘Browser’ in the menu.
2. On Chainlist, you now need to connect your wallet. Your currently selected account will be the one that’s automatically connected, though you can easily swap by tapping the account icon in the top right and then selecting ‘Connect wallet’ again.
3. Next, find the network you want to connect to by searching. When you find the network, hit ‘Add Chain’:
4. Now you’ll just need to approve the addition of the network. There will then be a subsequent option to confirm that you want to immediately switch to the new network. This step is optional, and you can easily change networks at any time regardless.
Please note Metamask do not maintain the network information on Chainlist. Make sure the network details are accurate before adding them.