Ethereum is no longer just one chain. Today, users hold assets across Ethereum, Arbitrum, Base, Polygon, and more. A single wallet can have tokens, DeFi positions, and activity spread across multiple networks.
For developers, this creates a problem.
Getting a complete picture of a wallet means connecting to multiple chains, handling different data formats, and stitching everything together.
At CoinAPI, we work with developers building trading platforms, analytics tools, and financial products.
And one pattern keeps showing up:
- Raw blockchain data is powerful, but hard to use directly
- Developers don’t just need access - they need structured, usable data
Ethereum APIs are evolving in the same direction as financial data APIs:
- Less focus on nodes
- More focus on clean, aggregated, real-world data
That’s why this list focuses on APIs that actually help you build products faster, not just connect to the blockchain.
Best Ethereum APIs
1. CoinStats API
CoinStats Ethereum API is likely one of the easiest ways to manage Ethereum wallet data across multiple chains.
Instead of querying Ethereum, Polygon, Arbitrum, and others separately, CoinStats lets you pass one wallet address and get everything in a single response. This includes balances, ERC-20 tokens, DeFi positions, and even gas usage.
It supports all major EVM chains like Ethereum, Base, Optimism, and Avalanche. The response is already structured, so you don’t need to normalize data from different sources.
What you get:
- Multi-chain wallet balances (one API call)
- Automatic ERC-20 token detection
- DeFi positions (staking, lending, LPs)
- Transaction history with gas data
- Portfolio chart data
👉 Best for: portfolio trackers, wallet apps, DeFi dashboards
2. NOWNodes
NOWNodes gives you access to Ethereum data through a simple API without managing your own infrastructure. It supports multiple blockchains and lets you fetch balances, transactions, and block data in a straightforward way.
Compared to raw RPC providers, it’s easier to integrate and faster to get started.
What you get:
- Wallet and transaction data
- Multi-chain support
- Simple REST access
👉 Best for: quick integrations and multi-chain apps
3. Ethplorer
Ethplorer is a lightweight API focused on Ethereum token data and wallet tracking.
It’s simple and does one thing well: giving you access to token balances, transfers, and basic wallet insights without complexity.
What you get:
- Token balances and history
- ERC-20 token data
- Wallet-level insights
👉 Best for: simple apps and quick token lookups
4. Unmarshal
Unmarshal focuses on making blockchain data readable.
Instead of raw transaction data, it provides decoded, structured responses that are easier to use in apps.
It supports Ethereum and other chains, making it useful for cross-chain products.
What you get:
- Decoded transactions
- Wallet balances
- Token pricing data
👉 Best for: apps that need clean, human-readable blockchain data
5. Blocknative
Blocknative is all about real-time transaction data. It lets you track transactions in the mempool before they are confirmed, giving insight into gas fees, pending activity, and execution status.
What you get:
- Mempool data
- Transaction tracking
- Gas fee predictions
👉 Best for: improving UX and transaction visibility
6. Tatum
Tatum is a higher-level API that lets you build blockchain apps without deep blockchain knowledge. It abstracts complexity and provides tools for wallets, NFTs, and transactions through a single API.
What you get:
- Wallet creation and management
- Transaction handling
- NFT support
- Multi-chain APIs
👉 Best for: fast product development
7. Covalent API
Covalent focuses on structured blockchain data, not infrastructure or market feeds. It gives you a single API to access wallet balances, transactions, token data, and DeFi activity across Ethereum and other chains - all already indexed and normalized.
Instead of dealing with raw blockchain data, you get clean responses that are ready to use in apps.
What you get:
- Wallet balances and token holdings
- Transaction history (fully structured)
- NFT and DeFi data
- Unified API across multiple chains
👉 Best for: portfolio apps, dashboards, analytics tools
Where CoinAPI fits in
Ethereum APIs are great when you need on-chain data… wallets, transactions, DeFi activity… but many applications also need something else:
👉 market data
That’s where CoinAPI comes in.
CoinAPI focuses on:
- Real-time and historical crypto market data
- Trades, order books, OHLCV
- Aggregated data across hundreds of exchanges
- Clean, standardized APIs (REST, WebSocket, FIX)
Instead of tracking what’s happening inside wallets, CoinAPI helps you understand what’s happening in the market.
Why developers use CoinAPI:
- Reliable, normalized data across exchanges
- Low-latency feeds for trading apps
- Institutional-grade infrastructure
- Easy integration across multiple asset classes
👉 Best for: trading platforms, analytics dashboards, and financial products
Final thoughts
Ethereum is no longer a single-chain ecosystem.
Users are spread across multiple networks, and applications need to reflect that reality.
The best APIs today are not just about access… they’re about:
- aggregation
- clean data
- developer-friendly responses
Tools like CoinStats simplify blockchain data. Platforms like Blocknative add analytics layers… and alongside them, solutions like CoinAPI provide the market context that turns raw blockchain activity into meaningful insights.
If you’re building anything in crypto today, the winning stack isn’t one API.
It’s the right combination.
