Cross-Testnet Deployment Consistency Checker

WHAT IT DOES

This tool connects to your EVM wallet and checks the consistency of contract deployments across multiple testnet networks. It reads contract bytecode from deployment addresses on different chains, computes keccak256 hashes, and compares them to verify that identical bytecode is deployed everywhere. The tool also checks deployment status and code length for each deployment, helping developers ensure that their contracts are correctly and consistently deployed across all target testnets.

HOW TO USE

Connect your Web3 wallet using the Connect button. In the Deployments textarea, enter each deployment in the format name:address:chainId—one per line. For example, "Token:0x742d35Cc6634C0532925a3b844Bc454e4438f44e:5" for Goerli, "Token:0x742d35Cc6634C0532925a3b844Bc454e4438f44e:11155111" for Sepolia, and "Token:0x742d35Cc6634C0532925a3b844Bc454e4438f44e:97" for BNB Testnet. Click "Check Consistency" to fetch bytecode from each deployment and compare hashes. Click "Load Sample" to populate fields with example deployments. Results appear in the Results card with a summary of deployments checked, consistency status, and a detailed breakdown of each deployment showing its address, chain ID, bytecode hash, and code length.

TECHNICAL MECHANISM: BYTECODE HASH COMPARISON ACROSS NETWORKS

The tool uses ethers.js to fetch contract bytecode via provider.getCode(address) for each deployment on the currently connected network. It determines if the contract is deployed (code is non-empty) and computes the keccak256 hash of the bytecode using ethers.utils.keccak256(). The tool then compares the hashes of all successfully fetched bytecodes. If all hashes match, the deployments are considered consistent. Each deployment's code length and deployment status are also displayed for diagnostics. The tool requires the connected wallet to have access to the RPC endpoints for each target chain.

WHAT IT CANNOT SEE

This tool cannot verify that different bytecode reflects intended differences or deployment errors—the tool only detects differences, not their cause. It cannot detect semantic differences between contracts with same bytecode but different state—state is not compared. It cannot automatically determine if deployment parameters are correct for each network—the tool only checks bytecode. It relies on on-chain bytecode queries and may be rate-limited by RPC providers—multiple queries may be throttled. It cannot compare contracts across networks with different compiler versions or optimizations—the tool only compares bytecode, not build settings.

PLEASE NOTE

This is a read-only tool—it never signs transactions. All data is fetched on-demand and stored only in memory; nothing is persisted across page reloads. The tool supports EVM chains only—Ethereum, Polygon, BSC, Arbitrum, Optimism, Base, and their testnets. The tool compares bytecode hashes—if bytecode differs, the contract may have been deployed with different source code, compiler settings, or constructor arguments. Always ensure deployment parameters are consistent across networks for reliable cross-chain contract behavior.