Ethplorer API

Cryptocurrency / API Key Intermediate HTTPS
Varies by plan (check documentation)

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

coin price in USD/EUR
market capitalization
24h price change
trading volume
circulating supply

Example Response

JSON 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

Error: request limit reached Exceeding the freekey rate limit, which allows roughly 1-2 requests per second
Add a 1-second delay between requests in loops, or register for a paid key at ethplorer.io for higher throughput.
Empty token list for an address Querying an address that holds no ERC-20 tokens or has never interacted with any token contract
Verify the address is correct using a block explorer like etherscan.io; native ETH balances are shown in the ETH field, not in the tokens array.
Invalid address format Passing an address without the 0x prefix or with incorrect checksum casing
Always include the 0x prefix and ensure the address is 42 characters total; use lowercase to avoid checksum issues.

Matrix Score Breakdown

🌐 Reachability 30/30
⚡ Speed 10/20
🔒 Security 15/15
🛠 Developer XP 12/20
✓ Reliability 10/15

Partially tested on Apr 5, 2026

Technical Specifications

Auth API Key
HTTPS REQUIRED
CORS UNKNOWN
Category Cryptocurrency
Difficulty Intermediate
Verified: 2026-04-04

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