Event Log Decoder
Named fields from topics and data, given the event signature.
Runs offline
Paste an event signature, its topics, and data to decode named fields.
About event log decoder
A log has up to four topics and a data blob. Indexed parameters go into topics so they can be filtered on; everything else is packed into data. That split is decided by the indexed keyword in the event declaration, which is why decoding fails if you drop it from the signature. Topic zero is the hash of the event signature itself.
Common questions
How do I decode an Ethereum event log?
Paste the topics and data with the event signature. Indexed fields live in topics; the rest sit in data. This reassembles them into named fields so a raw log becomes readable without a full explorer UI.
Why do some fields appear in topics and others in data?
Solidity puts indexed parameters into topics and non-indexed parameters into data. Knowing which is which is required to decode correctly; guessing swaps values silently.
Do I need the contract ABI?
You need the event signature with name and types. A full ABI works when you have one; a single event line is enough here. Without either, the log stays opaque hex.