As blockchain development continues to evolve, understanding the core configurations of various networks—such as Chain IDs, RPC URLs, and block explorers—has become essential for developers building decentralized applications (dApps). Whether you're deploying smart contracts, integrating wallet connectivity, or testing across environments, having quick access to accurate network details saves time and reduces errors.
This guide compiles critical information for major blockchain networks including Ethereum, Polygon, xDai (now Gnosis Chain), Shiden, and Avalanche, covering both mainnets and testnets. All data is structured for clarity and developer convenience, with Hex and Decimal Chain IDs, RPC endpoints, and block explorer links.
Ethereum Network Details
Ethereum remains the foundation for most decentralized ecosystems. Knowing its network specifications is crucial for any Web3 developer.
Mainnet & Testnets Overview
| ChainID | Hex | Decimal | Network | RPC URL | Block Explorer URL |
|---|---|---|---|---|---|
| 1 | 0x1 | 1 | Ethereum Main Network | https://mainnet.infura.io/v3/ | https://etherscan.io |
| 3 | 0x3 | 3 | Ropsten Test Network | https://ropsten.infura.io/v3/ | https://ropsten.etherscan.io/ |
| 4 | 0x4 | 4 | Rinkeby Test Network | https://rinkeby.infura.io/v3/ | https://rinkeby.etherscan.io/ |
| 5 | 0x5 | 5 | Goerli Test Network | https://goerli.infura.io/v3/ | https://goerli.etherscan.io/ |
| 42 | 0x2a | 42 | Kovan Test Network | https://kovan.infura.io/v3/ | https://kovan.etherscan.io/ |
🔍 Tip: While Rinkeby and Ropsten are being phased out due to PoS transition, Goerli is currently the recommended Ethereum testnet.
👉 Access Ethereum-compatible tools and APIs for faster dApp deployment.
Polygon (Matic) Network Configuration
Polygon offers a scalable solution for Ethereum-based dApps with low transaction fees and high throughput.
Mainnet & Mumbai Testnet
| ChainID | Hex | Decimal | Network | RPC URL | Block Explorer URL |
|---|---|---|---|---|---|
| 137 | 0x89 | 137 | Polygon Mainnet | https://rpc-mainnet.maticvigil.com/ | https://polygonscan.com/ |
| 80001 | 0x13881 | 80001 | Mumbai Testnet | https://rpc-mumbai.maticvigil.com/ | https://mumbai.polygonscan.com/ |
🚀 Polygon’s PoS chain is widely adopted by gaming and DeFi projects due to fast finality and EVM compatibility.
Gnosis Chain (formerly xDai) Networks
Gnosis Chain (previously known as xDai) focuses on stable transaction fees using a dollar-pegged token, making it ideal for micropayments and social dApps.
Gnosis Mainnet & Sokol Testnet
| ChainID | Hex | Decimal | Network | RPC URL | Block Explorer URL |
|---|---|---|---|---|---|
| 100 | 0x64 | 100 | Gnosis Mainnet | https://rpc.xdaichain.com/ | https://blockscout.com/xdai/mainnet/ |
| 77 | 0x4d | 77 | Sokol Testnet | https://sokol.poa.network/ | https://blockscout.com/poa/sokol/ |
💡 The Gnosis Chain uses a Proof-of-Authority consensus model, ensuring fast and reliable transactions.
Shiden Network (Astar Ecosystem)
Shiden is a multi-chain platform built on the Kusama network, supporting EVM, WASM, and Layer2 solutions.
Shiden & Shibuya Networks
| ChainID | Hex | Decimal | Network | RPC URL | Block Explorer URL |
|---|---|---|---|---|---|
| 336 | 0x150 | 336 | Shiden Mainnet | https://rpc.shiden.astar.network:8545/ | https://shiden.subscan.io/ |
| 81 | 0x51 | 81 | Shibuya (Parachain Testnet) | https://rpc.shibuya.astar.network:8545 | https://shibuya.subscan.io |
⚙️ Shiden enables cross-virtual machine interoperability—ideal for developers exploring hybrid smart contract architectures.
👉 Explore multi-chain development tools that support EVM and non-EVM environments.
Avalanche Network Specifications
Avalanche stands out with its sub-second finality and custom subnet capabilities, making it a favorite among institutional-grade dApp builders.
C-Chain: Contract Chain
| ChainID | Hex | Decimal | Network | RPC URL | Block Explorer URL |
|---|---|---|---|---|---|
| 43114 | 0xa86a | 43114 | Avalanche Mainnet (C-Chain) | https://api.avax.network/ext/bc/C/rpc | https://snowtrace.io/ |
| 43113 | 0xa869 | 43113 | Fuji Testnet (C-Chain) | https://api.avax-test.network/ext/bc/C/rpc | https://testnet.snowtrace.io/ |
⚡ Avalanche’s unique consensus mechanism allows thousands of validators to participate without sacrificing speed.
Frequently Asked Questions
What is a Chain ID?
A Chain ID is a unique identifier used in Ethereum-based blockchains to prevent transaction replay across different networks. It ensures that a transaction signed on one chain (e.g., Ethereum Mainnet) cannot be broadcast on another (e.g., Polygon).
How do I add these networks to MetaMask?
To manually add a network in MetaMask:
- Open MetaMask → Settings → Networks → Add Network.
Enter:
- Network Name
- New RPC URL
- Chain ID (Decimal)
- Currency Symbol (e.g., MATIC, AVAX)
- Block Explorer URL
👉 Use trusted infrastructure to securely connect wallets and deploy contracts across chains.
Why are Hex and Decimal formats both important?
Smart contracts and Web3 libraries often require Hex format (e.g., 0x89) when interacting at the protocol level, while wallet interfaces like MetaMask typically accept Decimal values during manual network configuration.
Are all testnets still active?
No. Some older Ethereum testnets like Rinkeby and Ropsten have been deprecated after the Merge (transition to Proof-of-Stake). Developers should now use Goerli or Sepolia for testing.
Can I use Infura for non-Ethereum networks?
Yes! Infura supports multiple chains including Polygon, Avalanche, Arbitrum, Optimism, and Gnosis Chain. Using Infura improves reliability compared to public RPC endpoints.
How can I verify a network's RPC URL?
Always refer to official documentation or community-verified sources like:
- Chainlist.org
- Official blockchain GitHub repos
- Developer portals (e.g., docs.avax.network)
Avoid untrusted third-party lists to prevent security risks.
Core Keywords for SEO
- Blockchain Chain ID
- Ethereum RPC URL
- Polygon Mainnet configuration
- Gnosis Chain details
- Avalanche Fuji testnet
- Shiden Network setup
- Web3 development tools
- Multi-chain dApp deployment
These keywords naturally reflect search intent around blockchain integration, network configuration, and smart contract deployment.
By referencing this guide, developers can streamline their workflow, reduce configuration errors, and accelerate cross-chain dApp development—all while maintaining compatibility with leading wallets and infrastructure providers.