MetaMask is a crypto wallet app and browser extension that by default is connected to the Ethereum mainnet. You can find the extension on the official MetaMask website, which will direct you to the correct place to download it.
To connect to other networks like Polygon, you'll need to add some basic blockchain information to MetaMask. This includes a custom RPC URL, chain ID, and network name. To add Polygon tokens, a token address must be imported.
Learning to add a new blockchain to MetaMask is a transferable skill and can be used to add other EVM networks like Binance Smart Chain.
Installing and setting up MetaMask
After downloading and installing the extension, you’ll be greeted with the MetaMask welcome page. Click [Get Started] to begin.
MetaMask will ask you if you’d like to share anonymous usage data with them to help improve the extension. Accepting or refusing this will not affect your MetaMask usage.
Choose a secure password to log in to your wallet from your browser. Note that this is not your seed phrase. The password is a security measure to prevent anyone using your device from accessing your wallet. If you forget your password, you can always access your crypto with your seed phrase.
After choosing your password, MetaMask will present you with information regarding your wallet’s seed phrase. Make sure to read through it if you aren’t familiar with how a crypto wallet works.
You’ll now be presented with your seed phrase. Click the lock to view the words and take note of them in the correct order. Keep the phrase in a secure place (preferably offline) and never share it with anyone. This string of numbers is the final backup of your wallet and its contents. Click [Next] to continue.
You’ll now have to repeat your seed phrase by selecting the words at the bottom of the screen in the right order. Click [Confirm] once this is complete.
Your MetaMask wallet will now be set up ready to use. Click [All Done] to view your wallet.
Configuring the wallet
Adding Polygon support to your wallet involves adding some network details to the extension. First, open MetaMask and click the network dropdown menu.
Now, click [Add Network] on the pop-up.
You’ll need to add the following details on the [Add a network] page that will open. Click [Save] when you’re finished.
You’ll now successfully be connected to the Polygon network.
Adding Polygon tokens to MetaMask
For Polygon tokens other than MATIC to appear on the wallet UI, you will need to add them manually. Note that your wallet can still receive tokens that haven’t been imported.
Return to MetaMask and click [Import tokens].
Copy in the token’s contract address and MetaMask should automatically fill in the rest of the details. If not, add them manually. To finish, click [Add Custom Token].
Click [Import Tokens].
Your wallet will now successfully display the balance of the token added.