Blockchain Event Log Viewer

WHAT IT DOES

Blockchain Event Log Viewer gives you a clean, structured view of all event logs emitted by any EVM contract. Enter a contract address and optionally provide an ABI to decode events into human-readable names and argument values. The tool fetches logs from the last 20,000 blocks and displays them with block numbers, transaction hashes, and full topic/data fields. If you provide an ABI, it decodes each log into the event name and a formatted JSON object of its arguments, making it easy to understand what the contract is doing. You can also filter by a specific event signature topic to narrow down the results.

HOW TO USE

Connect your EVM wallet (optional—the tool works read-only). Select the network from the dropdown. Enter the contract address and optionally paste an ABI JSON array (containing event definitions) in the text area. You can also add a topic filter (event signature hash) to limit the results. Click "view logs" to fetch and decode logs from the last 20,000 blocks. The tool displays each log with its block number, transaction hash, and either decoded event data (if ABI provided) or raw topics and data. Use the "clear" button to reset and start a new query. No signing or transactions required.

TECHNICAL MECHANISM

The tool uses ethers.js v5.7.2 via the BGWallet provider. It constructs a filter with the contract address and optional topic array, then calls provider.getLogs() using a chunked fetcher that automatically halves block ranges on RPC limit errors—ensuring the scan completes even on public nodes with strict eth_getLogs caps. If an ABI is provided, the tool creates an ethers.utils.Interface and uses it to parse each log with interface.parseLog(), extracting the event name and decoded arguments. The results are displayed in a clean, collapsible format with block numbers, transaction hashes, and full decoded data. Raw logs are shown with topics and data fields for reference.

WHAT IT CANNOT SEE

This tool cannot decode events without a matching ABI—you must provide the ABI for the contract. It cannot read events from before the archive node's earliest block—older logs may be unavailable. It cannot decode events from private or unverified contracts. It cannot track events across multiple contracts in a single query—only one contract at a time. It cannot detect or decode custom event structures that do not conform to standard ABI encoding. It cannot query the mempool or pending logs. Historical data is limited by the RPC provider's archive node availability; block ranges may vary. It does not monitor logs in real-time—only point-in-time queries.

PLEASE NOTE

Works exclusively on EVM-compatible chains: Ethereum Mainnet, Goerli, Sepolia, Polygon, Arbitrum, and Optimism. Solana, Tron, Starknet, SUI, TON, Aptos, Bitcoin, Cosmos, and XRP are not supported. This is a read-only, free developer tool—use it for debugging and contract monitoring, but always cross-check critical logs with a block explorer or your own node.