Call Stack Visualizer for Failed Transactions

WHAT IT DOES

This tool connects to your EVM wallet and analyzes failed transactions by reading transaction receipts, revert reasons, and call traces from on-chain data. It displays the transaction status, revert reason, gas usage, and call stack information. With an optional contract ABI, the tool decodes event logs and call stack entries to provide human-readable insights into why a transaction failed, making it easier to debug contract interactions and identify the root cause of errors.

HOW TO USE

Connect your Web3 wallet using the Connect button. Enter the transaction hash of the failed transaction in the Transaction Hash field. Optionally, enter the contract ABI in JSON format to enable decoding of event logs. Click "Analyze Transaction" to fetch and display transaction details, revert reason, and call stack. Click "Decode Call Stack" to attempt decoding of logs using the provided ABI. Results appear in the Results card with transaction status, revert reason, call depth, and a detailed breakdown of logs and decoded events.

TECHNICAL MECHANISM: TRANSACTION RECEIPT ANALYSIS AND LOG DECODING

The tool uses ethers.js to fetch transaction receipts via provider.getTransactionReceipt(hash) and transaction details via provider.getTransaction(hash). The receipt includes transaction status (success/failure), gas used, effective gas price, and logs. The revert reason is extracted from the receipt's revertReason field when available. The call stack is represented by the transaction's logs, which are displayed with address, topics, and data. When an ABI is provided, the tool uses ethers.utils.Interface to parse logs and decode events, converting raw data into human-readable event names and argument values. The tool also displays transaction metadata including sender, recipient, and gas details.

WHAT IT CANNOT SEE

This tool cannot access debug_traceTransaction without an archive node or appropriate RPC permissions—most public RPCs do not support this method. It cannot reconstruct call stack for transactions that are not indexed or available—the transaction must be on-chain and accessible. It cannot decode call stack entries without corresponding contract ABI—the ABI is required for meaningful decoding. It cannot determine the exact cause of failure beyond what is captured in the revert reason—some failures may have minimal information. It relies on RPC support for trace methods and may not work with all providers—some RPCs may not support the required methods.

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, Avalanche, Base, and Fantom. Not all RPC providers support trace methods—consider using an archive node or dedicated tracing provider for full call stack information. The revert reason may not always be available for all failed transactions.