What is Etherscan and what is it used for?

Etherscan is a block explorer for Ethereum, a search engine for the Ethereum blockchain. You can paste in a transaction hash, wallet address, token or block number and see the public record behind it. It is run by a company, not by Ethereum itself.

What is Etherscan.io and who runs it?

Etherscan.io is the address of the explorer. According to its own about page, the explorer launched in August 2015, and its API followed a month later. Matthew Tan is listed as founder and CEO. The company describes itself as one of the earliest independent projects built around Ethereum.

Etherscan also runs other explorers, as of November 2026. These include Blockscan for many chains, BeaconScan for Ethereum's consensus layer, explorers for test networks such as Sepolia, and Solscan for Solana, which it acquired in January 2024.

What is Etherscan used for?

Our step-by-step guide on how to use a blockchain explorer covers looking up a transaction. Beyond that, people use Etherscan to:

• Read smart contracts. Projects can verify a contract, which means publishing source code that Etherscan confirms matches the code on the chain. A verified contract shows a green check mark, but Etherscan warns this does not mean the contract is safe or audited.
• Interact with contracts. The Read Contract tab shows public data at no cost. The Write Contract tab lets you connect a wallet and send transactions directly, which costs gas and is usually irreversible.
• Review token approvals. The Token Approval tool lists which apps can spend your tokens, and lets you revoke approvals you no longer need.
• Check fees. A gas tracker shows current network gas fees.
• Export data. Address histories can be downloaded as CSV files.

Name tags and third-party security labels on Etherscan help spot known scam tokens and addresses. Etherscan says it does not audit or guarantee contracts, so the person signing is responsible for each transaction.

What is an Etherscan API key?

The Etherscan API lets developers fetch blockchain data, such as balances and transaction lists, from code instead of a browser. Etherscan's docs say you create a key by signing up for a free account and opening the API dashboard. The key identifies your requests so Etherscan can manage rate limits and prevent abuse.

In May 2025 Etherscan moved to API V2, which merged the separate keys for each chain into one. Etherscan said one key now works across more than 60 EVM-compatible chains, with the chain chosen by its chain ID. Paid plans add higher rate limits. A key is a login for data, not a wallet key, and cannot move funds.

What is Etherscan in blockchain terms?

Etherscan is not part of the blockchain. It reads data from Ethereum nodes and displays it, so it cannot hold, freeze, speed up or reverse anything. Etherscan notes that write actions are signed in your own wallet and sent to an Ethereum node. If Etherscan went offline, the network and your funds would carry on. Each smart contract and transaction would still exist, just viewed through a different explorer.