MetaMask is one of the most-used crypto wallets: a free browser extension (and phone app) that holds your keys and talks to blockchains. Out of the box it speaks to Ethereum. Polygon is a separate network — faster and much cheaper per transaction — and MetaMask needs its details before it can connect. This guide walks the whole path in order: install, secure, add Polygon, fund it with a little POL for gas. Nothing here is a push to buy anything; it's plumbing knowledge, like knowing where your water shutoff is.
Step 1: Install MetaMask the safe way
- Type metamask.io into your browser yourself. Don't click ads or search results — fake MetaMask sites exist and they steal.
- Follow the official link to your browser's extension store and check the publisher name and the download count before installing.
- Open the extension and choose "Create a new wallet."
- Set a strong password. This password only protects the wallet on this device — it is not the master key. That comes next.
Step 2: Protect your seed phrase like it's the whole wallet (it is)
MetaMask now shows you a seed phrase — usually 12 random words, also called a Secret Recovery Phrase. Those words ARE your wallet. Anyone who has them controls your funds from any device on Earth, and no password stops them.
- Write the words on paper, in order, and check your spelling. Store the paper somewhere safe at home. Consider a second copy in a second place.
- Never photograph it, screenshot it, email it to yourself, or save it in notes or cloud storage. Hacked accounts leak, and thieves search them for word lists.
- Never type it into any website or app, no matter what the page claims. MetaMask itself only asks for it when YOU choose to restore a wallet on a new device.
- No support agent, airdrop, or "validation tool" ever needs it. Anyone asking is a thief. This is the one rule with zero exceptions.
If your wallet will eventually hold real savings, read about hot versus cold wallets too — a browser wallet is the convenient kind, not the vault kind.
Step 3: Add the Polygon network
Newer MetaMask versions list Polygon under Networks — open the network menu, find Polygon Mainnet, and enable it with one click. If yours doesn't, add it manually: network menu, then "Add a custom network," then enter these values exactly.
| Setting | Value |
|---|---|
| Network name | Polygon Mainnet |
| RPC URL | https://polygon-rpc.com |
| Chain ID | 137 |
| Currency symbol | POL |
| Block explorer | https://polygonscan.com |
Two notes. The RPC URL is the address MetaMask uses to talk to Polygon — type it carefully, because a wrong RPC can feed your wallet false information. And the network's gas token was renamed from MATIC to POL in 2024, so older guides (including the one that used to live at this URL) say MATIC. Same network, updated name. Save, switch to Polygon Mainnet, and your account address stays the same — one address works across these networks.
Step 4: Get a little POL for gas
Every action on Polygon — sending tokens, claiming things, swapping — costs a tiny fee called gas, paid in POL. No POL, no transactions; it's the quarter for the shopping cart. Fees on Polygon are usually a fraction of a cent, so a few dollars' worth lasts a long time. The common ways to get some: buy POL on a major exchange and withdraw it to your address using the Polygon network, or ask a trusted friend who uses Polygon to send you a dollar's worth. When withdrawing from an exchange, always double-check two things: the network says Polygon, and the address matches yours. Send a tiny test amount first.
Step 5: A quick safety shakedown
- Bookmark the sites you use, including polygonscan.com, and use bookmarks instead of search from now on.
- Treat every wallet pop-up as a contract. Read what it wants before approving — especially "approval" requests that let a site move your tokens.
- Unexpected tokens appearing in your wallet are usually bait. Ignore them; interacting is how airdrop-shaped scams hook people.
- Keep only spending money in this wallet, and remember our risk disclaimer: crypto can go to zero, and no wallet setup changes that.
Polygon in MetaMask, done right
That's the whole recipe: official install, seed phrase on paper, five network settings, a few dollars of POL, and a bookmark habit. Maybe twenty minutes of careful work, and you now have the same setup people use to interact with apps and claim legitimate airdrops on Polygon. The order matters more than speed — secure the seed phrase before the wallet ever touches money, and every later step gets calmer.