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.
Measurement Record
What actually happened when we called this API from our own infrastructure. Every value below was recorded by the request, not copied from the provider's documentation.
- Request
- GET https://api.ethplorer.io/getAddressInfo/0xd8da6bf26964af9d7eed9e03e53415d37aa96045?apiKey=freekey
- Result
- HTTP 200 · application/json · 2,363,638 bytes · compressed
- Response time
- 626 ms (median of 3) · fastest 443 ms
- Transport
- TLSv1.3 · TLS_AES_256_GCM_SHA384 · certificate issued by Google Trust Services
- Browser CORS
- Allowed — Access-Control-Allow-Origin: *
- Served by
- cloudflare
- Recorded
- 2026-08-10
Available Data
The kind of data this API exposes, based on its documentation. We could not call the endpoint to confirm the exact field names.
Example Response
Illustrative shape only — we were not able to call this endpoint (it requires credentials or exposes no public sample URL), so the fields below show the kind of data this API returns rather than a recorded 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
Calls a real endpoint of this API. Replace any placeholder credentials with your own key.
const url = "https://api.ethplorer.io/getAddressInfo/0xd8da6bf26964af9d7eed9e03e53415d37aa96045?apiKey=freekey";
// 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.
How This API Fails
We deliberately sent this API a broken request and recorded exactly what came back on 2026-08-10. Knowing the shape of an error before you hit it makes error handling much easier to write.
{
"error": {
"code": 17,
"message": "Invalid request, check API manual there: https://github.com/EverexIO/Ethplorer/wiki/Ethplorer-API"
}
} {
"error": {
"code": 1,
"message": "Invalid API key"
}
} Common Errors & Troubleshooting
Generated guidance based on this API's documentation, not observed by us. Treat it as a starting point and check against the provider's own error reference.
Measured Score Breakdown
Live HTTP request to the API endpoint
Fully tested on Aug 10, 2026
Technical Specifications
Related Tags
Similar APIs
View All →Binance
⭐ Beginner's PickBinance Spot API provides real-time and historical market data for thousands of cryptocurrency trading pairs on the world's largest crypto exchange by volume.
BitcoinAverage
BitcoinAverage aggregates price data from dozens of global cryptocurrency exchanges to produce weighted average prices for Bitcoin and other digital assets.
Bitfinex
Bitfinex is a professional cryptocurrency exchange offering one of the most comprehensive trading APIs for both spot and margin markets.
Bitmex
BitMEX is a derivatives exchange specializing in perpetual swaps and futures contracts for Bitcoin and other cryptocurrencies.
1inch
⭐ Beginner's Pick1inch is a decentralized exchange (DEX) aggregator that finds the best swap routes across protocols like Uniswap, SushiSwap, and Curve.