Testnet vs Mainnet Contract Checker

WHAT IT DOES

Testnet vs Mainnet Contract Checker is a read-only tool that analyzes contract addresses to determine whether they are deployed on testnet or mainnet, comparing them against known deployments and flagging mismatches. It reads contract address, deployed chain ID, bytecode hash, contract creation block, ABI and interface identifiers, source code verification status, deployment history, chain-specific deployment patterns, known testnet and mainnet contract addresses, associated token symbols and names, and block explorer metadata. The tool then presents this data alongside an AI-generated explanation of whether the contract appears to be on testnet or mainnet, comparison to known deployments, and any flagged mismatches or concerns — helping you avoid accidentally interacting with a contract on the wrong network.

HOW TO USE

Connect your wallet using the BGWallet bridge and select your target network. Enter the contract address you want to check. Optionally enter a contract name (e.g., USDC, WETH) for reference. Click "Check contract" to read on-chain data. The tool displays the contract address, chain ID, deployment status, bytecode hash, creation block, and source code verification status. Detailed information includes contract name, deployment pattern, known testnet address (if any), known mainnet address (if any), associated token, block explorer metadata, and mismatch flags. A risk level indicator (Low/Medium/High/Critical) helps you quickly assess the situation. An AI explanation appears below the on-chain data, describing whether the contract is on testnet or mainnet, comparing it against known deployments, and flagging any mismatches or concerns. The wallet's own signature step still protects you — this explanation is informational only and does not replace reviewing what you approve in your wallet.

TECHNICAL MECHANISM

The tool uses ethers.js v5.7.2 with the provider from the BGWallet bridge to read on-chain data from the contract you specify. No hardcoded contract addresses are used — you are always in control of which contract you trust. When checking a contract, the tool reads the deployed chain ID via provider.getNetwork() and compares it to the selected network, reads the bytecode hash via provider.getCode(contract) to compute the keccak256 hash for comparison, reads the contract creation block via provider.getTransactionReceipt() (for deployed contracts), checks source code verification status via the block explorer API or contract metadata, reads deployment history from the contract's transaction history, identifies chain-specific deployment patterns by comparing the contract's bytecode against known patterns, reads known testnet contract addresses from a local or API-based database, reads known mainnet contract addresses similarly, reads associated token symbols and names from the contract's metadata, and reads block explorer metadata via the API. The tool fetches event logs by walking backwards in chunks and halving chunk size on failure, ensuring logs are properly read despite varying RPC limitations. The data is formatted and passed to the AI bridge via BGAI.generate() with a structured prompt that includes all the on-chain data read. The AI is instructed to explain whether the contract is on testnet or mainnet, compare it against known deployments, and flag any mismatches or concerns — while stating plainly that it cannot verify contract source code correctness or detect malicious intent in the code itself, and cannot guarantee that a contract's behavior matches its verified source code beyond bytecode comparison. The AI response is capped at 1,024 tokens to ensure concise, focused contract assessments. All computed values are guarded against negative numbers — if a chain ID or block number appears invalid, the tool flags it rather than displaying nonsensical values.

WHAT IT CANNOT SEE

This tool cannot verify contract source code correctness or detect malicious intent in the code itself. It cannot detect clones or proxies that point to different implementations. It cannot guarantee that a contract's behavior matches its verified source code beyond bytecode comparison. The AI explanation is generated from on-chain data only and cannot detect hidden malicious code, proxy implementation changes, off-chain contract behavior, or intent behind the deployment. It cannot predict future contract upgrades, ownership changes, or potential scams. The tool does not continuously monitor the contract; each analysis is a snapshot at the time of the lookup. It cannot detect delayed verification status, proxy pattern changes, or off-chain metadata updates. The tool does not store any data persistently; all state is in-memory and resets on reload. The AI explanation is informational and does not constitute financial advice, legal advice, or a guarantee of contract safety or correct network identification.

PLEASE NOTE

Testnet vs Mainnet Contract Checker works exclusively with EVM-compatible chains. It requires a Web3 wallet (MetaMask or similar) and the BGWallet bridge. Explanations are AI-generated from data the app reads on-chain — always review what you are actually signing in your wallet before approving it. Always verify the contract address you are using — the tool does not validate or endorse any contracts. Interacting with a contract on the wrong network carries significant risk including loss of funds, failed transactions, and unintended contract behavior. Use this tool as a guide only; always cross-check with the protocol's official documentation and block explorers for critical decisions. This is experimental software; use at your own risk.