Multi-Chain Transaction Trace Comparator

WHAT IT DOES

Multi-Chain Transaction Trace Comparator helps developers and auditors verify that a transaction executes identically across different EVM chains. You provide the same transaction hash from multiple chains (or different transactions you want to compare), and the tool fetches execution traces, receipts, and logs from each chain's RPC endpoint. It then presents a side‑by‑side comparison of status codes, gas usage, call traces, and emitted events. This is essential for cross‑chain applications, bridge validations, and ensuring deterministic behavior across Ethereum, Polygon, Arbitrum, and other EVM‑compatible networks.

HOW TO USE

Enter one transaction entry per line in the format: tx_hash,chain_id,rpc_url. You can use the same transaction hash across different chains to compare replay behavior, or use different hashes to compare similar transactions. Click "compare traces". The tool fetches transaction receipts and traces from each RPC endpoint using debug_traceTransaction or trace_transaction (with fallback to receipt data). Results are displayed with status indicators, gas usage, log counts, and an indented call trace. A summary shows whether all status codes match, highlighting discrepancies that may indicate different execution outcomes across chains.

THE REAL MECHANISM

The comparator uses ethers.js v5 to connect to each user‑provided RPC URL. It first fetches the transaction receipt to get the status, gas used, and logs. Then it attempts to retrieve a detailed trace using debug_traceTransaction with the callTracer for maximum detail. If that method is not supported (e.g., on some public RPCs), it falls back to trace_transaction, and finally to the receipt data alone. Each trace is normalized into a consistent format for display. The tool does not perform deep semantic analysis—it presents the raw trace data side‑by‑side so you can spot differences in call patterns, gas consumption, or revert reasons. All fetching is sequential to respect RPC rate limits.

WHAT IT CANNOT SEE

The tool cannot verify that traces are complete or accurate across all RPC providers, detect off‑chain transaction effects, handle chains without full trace support, compare transactions with different block timestamps or ordering, determine if differences are meaningful or benign, or access private or restricted RPC endpoints. Some chains do not support debug or trace methods, in which case only receipt‑level data is shown. Differences in gas pricing, block timestamps, or contract deployment addresses may cause legitimate variations that the tool cannot interpret.

PLEASE NOTE — EVM CHAINS ONLY

This tool is designed for Ethereum Virtual Machine (EVM) compatible chains that expose standard RPC methods for receipts and optional trace support. It does not work with non‑EVM chains. All processing occurs in your browser; no transaction data is stored or transmitted.