Ethereum Signature Database (4byte.directory)
key-free-public
Entirely free and key-free, with 1,460,431 function and event signatures in the database as of 2026-09-18. The site states the data is given free of any license or restrictions on how it may be used.
No numeric limit published. The only stated restriction is that usage must not disrupt the service; scraping is explicitly permitted 'with limited concurrency', and heavy users are encouraged to host their own copy of the data.
No paid tier.
n/a (free, no billing)
Chain-agnostic. Maps EVM 4-byte function selectors and 32-byte event topics back to human-readable signatures, so it applies to any EVM chain including Avalanche C-Chain and Robinhood Chain; it stores signatures, not chain state.
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fresh · last checked 2026-09-18
evm
- api.contract
- 4-byte function selector lookup
- 32-byte event topic lookup
- bulk scrape / self-host copy
Change history1 entries · newest first
- new service
Ethereum Signature Database (4byte.directory) added to the tracker (data_apis)verified
Newly tracked provider. Free tier: Entirely free and key-free, with 1,460,431 function and event signatures in the database as of 2026-09-18. The site states the data is given free of any license or restrictions on how it may be used. Rate limit: No numeric limit published. The only stated restriction is that usage must not disrupt the service; scraping is explicitly permitted 'with limited concurrency', and heavy users are encouraged to host their own copy of the data. Paid from: No paid tier.