How to Get Token Balances from an ETH Address

Understanding Token Balances on Ethereum

Tokens differ from ETH because they're stored as state within smart contracts rather than being directly associated with addresses. Ethereum addresses can be either:

• Contract addresses
• Externally Owned Accounts (EOAs)

Both types can hold ETH, which you can check using web3.getBalance(). However, tokens are held as part of a contract's internal state, typically stored in a mapping like:

mapping(address => uint256) balances

Step-by-Step Guide to Checking Token Balances

1. Identify Your Target Token

Before checking balances, you need to know:

• The specific token you're interested in
• The token's contract address

Ways to Find Token Contracts:

1. Official team announcements (beware of scams)
2. Etherscan's token pages (look for "ERC20 Contract" field)
3. ENS names (e.g., omg.thetoken.eth)
4. Trusted third-party sources

👉 Discover popular ERC20 tokens

2. Querying the Token Contract

For ERC20-compatible tokens, use the balanceOf method:

from ethtoken import token
omg = token("omg.thetoken.eth")
balance = omg.token_balance("0xE853c...51919")

How It Works Technically:

1. Generates ERC20 ABI from specifications
2. Creates contract object using Web3.py
3. Wraps in ConciseContract for simplified calls
4. Calls balanceOf(address)
5. Adjusts for token decimals

Checking Multiple Tokens

Since tokens exist in separate contracts, there's no native "list all tokens" function. However, you can:

1. Use curated token lists (like MyEtherWallet's collection)
2. Iterate through known contract addresses
3. Apply the same balanceOf method to each

FAQ Section

Q: Can I check token balances without coding?

A: Yes! Tools like Etherscan and MyEtherWallet provide user interfaces for checking balances.

Q: Why can't I see my tokens in my wallet?

A: Your wallet might need the token contract address added to "see" the tokens, though they're always stored in the contract.

Q: How often should I check token balances?

A: Balances update with each transaction. For frequent checks, consider using 👉 blockchain explorers or setting up alerts.

Q: Are all Ethereum tokens ERC20?

A: No, but ERC20 is the most common standard. Others include ERC721 (NFTs) and ERC1155.

Best Practices for Developers

1. Always verify contract addresses from multiple sources
2. Handle token decimals properly (most use 18)
3. Consider gas costs when checking many tokens
4. Use established libraries like Web3.js/Web3.py rather than writing raw calls

Remember: Token balances represent claims on smart contracts, not direct ownership like ETH. This fundamental difference shapes how you interact with them programmatically.