Tutorial: Etherscan vs Infura: Choosing the Right API for Your Blockchain Application

In this tutorial, we will compare Etherscan and Infura, two popular services for interacting with the Ethereum blockchain. Both provide APIs, but they serve different purposes and are suited for different types of applications. By understanding the strengths of each, you can choose the right one based on your specific use case, whether it involves querying blockchain data or interacting with the Ethereum network in real-time.

Prerequisites

• Basic understanding of Ethereum and blockchain concepts.
• Familiarity with APIs and programming in Node.js or any other language.

Step 1: Understanding Etherscan and Infura

Before diving into code examples, it's important to understand the core differences between Etherscan and Infura.

• Etherscan:
• Primarily a block explorer and data provider. It offers read-only access to Ethereum blockchain data such as transaction histories, balances, token transfers, and more.
• Does not allow real-time interaction with the blockchain (e.g., sending transactions).
• Ideal for querying historical data and performing analytics on blockchain data.
• Infura:
• Provides full node access to the Ethereum network, allowing developers to interact with the blockchain in real-time.
• Supports read and write operations, such as sending transactions, deploying smart contracts, and interacting with dApps.
• Best for applications that require real-time interaction with Ethereum, such as decentralized apps (dApps).

Step 2: When to Use Etherscan

You should use Etherscan when you need to read data from the Ethereum blockchain, such as querying transaction details, wallet balances, or token transfers. Etherscan is a powerful tool for building blockchain explorers or applications that focus on data analytics.

Example 1: Querying Wallet Balance Using Etherscan API

1. Create a file etherscanQuery.js to query a wallet balance.

const axios = require('axios');

// Replace with your actual Etherscan API key
const apiKey = 'YOUR_ETHERSCAN_API_KEY';

// Replace with the Ethereum address you want to query
const address = '0xYourEthereumAddress';

// Etherscan API URL to fetch wallet balance
const url = `https://api.etherscan.io/api?module=account&action=balance&address=${address}&tag=latest&apikey=${apiKey}`;

async function getWalletBalance() {
  try {
    const response = await axios.get(url);
    const balanceInWei = response.data.result;

    // Convert balance from Wei to Ether
    const balanceInEther = balanceInWei / 1e18;
    console.log(`Wallet Balance: ${balanceInEther} ETH`);
  } catch (error) {
    console.error('Error fetching balance:', error);
  }
}

getWalletBalance();

Explanation:

• API: This script sends a GET request to Etherscan's API to fetch the balance of the specified Ethereum wallet.
• Use Case: Ideal for applications needing read-only access to Ethereum data.

Step 3: When to Use Infura

Use Infura when you need to interact with the Ethereum blockchain in real-time. Infura allows you to send transactions, deploy contracts, and interact with smart contracts. It is essential for decentralized applications (dApps) and any use case where you need to write to the blockchain.

Example 2: Sending Ether Using Infura and Ethers.js

1. Create a file infuraTransaction.js to send a transaction.

const ethers = require('ethers');

// Replace with your Infura Project ID
const infuraProvider = new ethers.JsonRpcProvider('https://mainnet.infura.io/v3/YOUR_INFURA_PROJECT_ID');

// Replace with your wallet's private key
const privateKey = 'YOUR_PRIVATE_KEY';

// Create a wallet instance and connect it to Infura
const wallet = new ethers.Wallet(privateKey, infuraProvider);

// Replace with the recipient's Ethereum address
const recipientAddress = '0xRecipientEthereumAddress';

// Amount to send (in Ether)
const amountInEther = '0.01';

async function sendTransaction() {
  try {
    const tx = {
      to: recipientAddress,
      value: ethers.utils.parseEther(amountInEther),
      gasLimit: 21000, // Gas limit for a basic transaction
      gasPrice: await infuraProvider.getGasPrice() // Get current gas price from Infura
    };

    // Send the transaction
    const transaction = await wallet.sendTransaction(tx);
    console.log('Transaction Hash:', transaction.hash);

    // Wait for the transaction to be mined
    const receipt = await transaction.wait();
    console.log('Transaction Confirmed:', receipt);
  } catch (error) {
    console.error('Error sending transaction:', error);
  }
}

sendTransaction();

Explanation:

• API: This script uses Infura’s node access and Ethers.js to send Ether in real-time.
• Use Case: Essential for dApps, wallets, or any application needing to send transactions or interact with the blockchain live.

Step 4: Differences in Use Cases

Etherscan Use Cases:

• Data Analytics: Use Etherscan if you need to fetch historical data, such as transaction histories, token balances, or account balances.
• Blockchain Explorers: Ideal for building tools similar to Etherscan itself, where you query and display blockchain data to users.
• Read-Only Data: You can’t send transactions, but you can retrieve information about any Ethereum address, smart contract, or token transfer.

Infura Use Cases:

• Decentralized Applications (dApps): If you’re building an application that needs to interact with Ethereum in real-time, such as sending transactions or calling smart contract functions.
• Wallets: If you are developing a wallet application that needs to sign and broadcast transactions.
• Smart Contract Deployment: Use Infura to deploy or interact with smart contracts on the Ethereum blockchain.

Step 5: Performance and Scalability

Etherscan:

• Rate Limits: Etherscan’s free tier limits the number of API requests per second (usually around 5 per second). This is fine for querying data but can be limiting for large-scale applications that need to process a lot of data quickly.
• Pricing: Etherscan offers paid tiers that increase the API request limits.

Infura:

• Rate Limits: Infura’s free tier provides a generous number of requests (e.g., 100,000 requests per day) and supports more requests as you scale. This makes it more suitable for real-time dApps.
• Pricing: Infura’s paid plans offer higher limits and additional features like access to Layer 2 networks.

Step 6: Choose Based on Your Use Case

• Use Etherscan if:
• You only need to read blockchain data.
• You want to build tools for analytics or explorers.
• You don’t need to send transactions or interact directly with smart contracts.
• Use Infura if:
• You need to interact with the Ethereum blockchain in real-time.
• You’re building dApps, wallets, or tools that require transactions.
• You need to write data to the blockchain, such as sending Ether or deploying contracts.

Step 7: Combining Etherscan and Infura

In some cases, you might want to use both Etherscan and Infura. For example, you might use Etherscan to query transaction histories or token transfers, and Infura to send transactions or deploy contracts.

Example:

• Etherscan: Use to fetch transaction history and display it in your dApp.
• Infura: Use to allow users to send transactions or interact with smart contracts.

Conclusion

Etherscan and Infura serve different purposes in the Ethereum ecosystem. Etherscan is perfect for applications that need to query blockchain data, while Infura is essential for real-time interaction with the blockchain. By understanding the strengths of each, you can choose the best service for your project, or even combine them to build powerful Ethereum applications.