Ethplorer API

Cryptocurrency / API Key Intermediate HTTPS
55 C
Measured Score 0 50 100 Speed 4/30 Consistency 8/20 Security 20/20 Browser access 15/15 Transparency 8/15 TESTED 2026-08-10

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.

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

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.

JSON Response · Illustrative
{
  "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.

Request
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.

HTTP 404 Requesting a path that does not exist application/json
{
  "error": {
    "code": 17,
    "message": "Invalid request, check API manual there: https://github.com/EverexIO/Ethplorer/wiki/Ethplorer-API"
  }
}
HTTP 401 Sending an invalid value for "apiKey" text/html
{
  "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.

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.

Measured Score Breakdown

Live HTTP request to the API endpoint

Speed 4/30
Consistency 8/20
Security 20/20
Browser access 15/15
Transparency 8/15
Endpoint Response Time 626ms

Fully tested on Aug 10, 2026

Technical Specifications

Auth API Key
HTTPS REQUIRED
CORS UNKNOWN
Category Cryptocurrency
Difficulty Intermediate
Endpoint last called: 2026-08-10

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