Overview
Ethplorer is a free REST API for exploring the Ethereum blockchain, offering detailed information about ERC-20 token holdings, wallet balances, transaction history, and token contract metadata. A free API key (freekey) is built in, so you can make read-only calls instantly without registration — paid keys lift rate limits and unlock bulk endpoints. It is particularly useful for building portfolio trackers or token analytics dashboards.
Beginner Tip
You can use the literal string freekey as your API key to start making calls right away without registration. To look up a wallet, replace the example address with any 0x Ethereum address and you will immediately see all ERC-20 tokens it holds.
Available Data
Example Response
{
"id": "bitcoin",
"symbol": "btc",
"current_price": 65432.1,
"market_cap": 1280000000000,
"price_change_24h": 1250.5,
"price_change_percentage_24h": 1.95,
"total_volume": 28500000000
} Field Reference
address The Ethereum address that was queried, returned in lowercase hex format. ETH.balance Native Ether balance of the address in ETH (not wei); already divided by 10^18. tokens[].tokenInfo.symbol Ticker symbol of the ERC-20 token, e.g. USDC or UNI. tokens[].balance Raw token balance in the token smallest unit; divide by 10 to the power of tokenInfo.decimals to get the human-readable amount. tokens[].tokenInfo.price.rate Current USD price per token unit, sourced from exchange data; may be absent for tokens with no active market. Implementation Example
const url = "https://github.com/EverexIO/Ethplorer/wiki/Ethplorer-API";
// Replace headers or query params with the values required by this API.
const response = await fetch(url, {
headers: {
"X-API-Key": "YOUR_API_KEY"
}
});
if (!response.ok) throw new Error(`Request failed: ${response.status}`);
const data = await response.json();
console.log(data); What Can You Build?
Note: These code examples are AI-generated and unverified. Always refer to the official API documentation for accurate usage.
Common Errors & Troubleshooting
Matrix Score Breakdown
Partially tested on Apr 5, 2026
Technical Specifications
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