This guide shows how to add custom networks to the MetaMask software wallet (both extension and mobile), with concrete RPC and Chain ID examples, safety checks, and reproducible tests. If you searched for "how to add polygon to metamask wallet" or "how to add polygon network to metamask" (or mobile variants like "how to add smart chain to metamask mobile"), you'll find step-by-step instructions here plus a safety checklist.
I run these changes daily when testing DeFi dApps, so I explain exactly how I verified each step (so you can repeat it). I've made mistakes here before, like adding an incorrect Chain ID and sending tokens to the wrong network — learned the hard way. And yes, double-check the Chain ID before sending funds.
Adding a custom network (via a custom RPC) lets a software wallet interact with EVM-compatible chains beyond the default list. That unlocks lower-fee swaps, L2 activity, and access to specific DeFi apps. But there are trade-offs:
Which fields matter most? The RPC URL and Chain ID. Everything else is convenience. (More on that below.)
When you click Add Network you'll be asked for five fields. Here are what they mean and why they matter:
If you want to add Polygon specifically, you can follow the dedicated walkthrough at add-polygon-to-metamask. For Smart Chain (BSC) mobile guidance see add-bsc-smart-chain-to-metamask.
This answers the classic search: how to add polygon to metamask wallet.
If you want a focused guide specifically on adding Polygon, see add-polygon-to-metamask.
Many people ask "how to add polygon to metamask mobile" or "how to add smart chain to metamask mobile". The mobile UI is similar.
Example Smart Chain (BSC) values for the mobile form (for reference only):
But don't paste RPCs you find in comment sections — verify the source.
| Task | Extension (desktop) | Mobile (iOS/Android) |
|---|---|---|
| Menu path | Network dropdown → Add Network | Menu → Settings → Networks → Add Network |
| Copy/paste RPCs | Easy with keyboard | Easy, but double-check fields before saving |
| Switching networks | Instant in most cases | Instant but UI differs slightly |
| Best for testing dApps | Desktop dApps via browser | Mobile dApp browser or WalletConnect |
I ran the same steps on both extension and mobile, using public RPC endpoints and a small live value (about $1 worth of native token) to verify submission and confirmations.
Steps I repeated for reproducibility:
I repeated these steps 3 times and recorded whether the RPC timed out, how long the first block load took, and whether token balances showed automatically. You can repeat the same checks.
But don't panic — adding networks is routine when you follow these steps.
If things still fail, consult troubleshooting or the network-specific page (for Polygon, see add-polygon-to-metamask).
Best for:
Should look elsewhere:
If your daily workflow involves frequent swaps, adding networks reduces friction. If you rarely move funds, a hardware-first approach is safer.
Q: Is it safe to keep crypto in a hot wallet? A: Hot wallets are convenient for DeFi activity but carry more risk than offline storage. Use seed phrase backups, hardware wallets for larger balances, and daily security practices (see security-and-safety).
Q: How do I revoke token approvals after connecting to a dApp? A: Use the token approvals revoke tool inside the wallet or a third-party revocation site, and double-check contract addresses. See token-approvals-and-revoke for step-by-step instructions.
Q: What happens if I lose my phone? A: If you have your seed phrase backed up offline, you can restore your wallet on another device (see backup-and-recovery-seed-phrase). If not, recovery is unlikely.
Q: Where can I find step-by-step mobile install details? A: See install-metamask-mobile and mobile-setup for first-time setup guidance.
Adding custom networks to MetaMask is a straightforward way to expand your DeFi access. Follow the exact fields for RPC and Chain ID, test with a small amount, and verify via the block explorer. In my experience the small test transaction saves headaches later.
If you want a deep walkthrough for a particular chain, check the chain-specific pages: add-polygon-to-metamask, add-bsc-smart-chain-to-metamask, and add-avalanche-avax-to-metamask. For safety-focused reading, see security-and-safety and backup-and-recovery-seed-phrase.
Ready to try? Add one network with a tiny test transaction, confirm it on the explorer, and then connect to the dApp you need. But always start small.