Event Signature Database Lookup Tool

WHAT IT DOES

Event Signature Database Lookup Tool is a developer-focused utility that resolves event signature hashes (topic0) to their human-readable event signatures using a built-in database of common EVM events. It accepts either a 32-byte topic0 hash (0x-prefixed) or an event signature string (e.g., "Transfer(address,address,uint256)") and searches for matches. When a hash is provided, the tool displays the corresponding event signature, parameter list, and source standard (ERC-20, ERC-721, EIP-1967, Uniswap, Aave, etc.). When a signature string is provided, the tool reverses the lookup to find the corresponding hash. The tool includes partial matching for both hashes and signatures, showing all possible matches when an exact match is not found. This enables developers to quickly identify events when reading transaction logs or debugging contract interactions without manually searching external signature databases.

HOW TO USE

Connect your wallet (optional). Enter a topic0 hash (e.g., "0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef") or an event signature string (e.g., "Transfer(address,address,uint256)") into the input field. Click "Look up" to search the database. The tool will display the match type (exact or partial) along with the signature, parameter list, and source standard. Partial matches show all possible results, allowing you to identify the correct event from context. The database includes common signatures from ERC-20, ERC-721, ERC-1155, EIP-1967 proxies, Uniswap V2/V3, Aave, Chainlink, ENS, OpenZeppelin Access Control, and other widely used standards.

TECHNICAL NOTE: DATABASE STRUCTURE AND SEARCH ALGORITHM

The tool uses a curated database of over 30 common event signatures, each mapped to its 32-byte Keccak-256 hash. The search algorithm first normalizes the input: if the input is a 0x-prefixed 66-character string, it is treated as a hash and looked up directly. If the input contains parentheses, it is treated as a signature string. The tool attempts exact matches first, then falls back to partial matching for both hashes and signatures. For signature strings, the tool removes whitespace before matching to handle variations in formatting. Partial matching is case-sensitive and uses simple substring inclusion, showing all entries that contain the query string. The database is maintained in-memory and does not require external network calls, making the lookup instant and reliable.

WHAT IT CANNOT SEE

The tool cannot resolve event signatures that are not in the built-in database, including custom events defined in your contracts or events from less common protocols. It cannot decode events without the full ABI; the tool only provides the signature and parameter list, not the actual decoded values. It cannot handle function signatures that use non-standard naming conventions or alternative parameter type encodings. It cannot resolve private or custom event signatures that have not been publicly documented. The tool is limited by the database's coverage; currently it includes approximately 30 common signatures. It cannot resolve signatures for non-EVM chains. It cannot validate that a resolved signature matches the actual event structure; the database entries are based on standard definitions and may not reflect contract-specific variations.

PLEASE NOTE

This tool is designed exclusively for EVM-compatible chains (Ethereum, Polygon, BSC, Arbitrum, Optimism, Avalanche C-Chain, etc.). It does not support non-EVM blockchains. The tool is read-only and does not connect to any external API or make RPC calls; all lookups are performed locally against the built-in database. The database includes only the most common event signatures; for custom or less common events, consider using the contract's verified source code or an external signature database. Always verify that a resolved signature matches the actual event definition in the contract source code.