In the context of blockchain technology, an "uncle" is a block that is not included in the main chain of a blockchain, but that is still valid and has been accepted by some nodes in the network. Uncles are typically created when two or more miners solve a block at the same time, and the network must choose which one to include in the main chain.

  • Uncle block: the block that is not included in the main chain
  • Uncle number: the position of the uncle block in the chain of uncles
  • Uncle hash: the unique identifier for the uncle block
  • Uncle reward: the amount of cryptocurrency that is awarded to the miner who created the uncle block
  • Uncle status: whether the uncle block is accepted by the network or not


The uncles data provided by Amberdata are for the Ethereum network and include information on the number of uncles that have been mined, as well as the block numbers and details of the uncle blocks themselves. Query the data by a specific hash or by a specified time period. Amberdata provides all uncles back to the genesis block of Ethereum, but due to the September 15, 2022 merge to Proof-of-Stake (PoS) consensus mechanism on the Ethereum network, blockchain uncles are now primarily a historical dataset. While unlikely, uncles may theoretically still appear and be tracked using the endpoints below.

Amberdata has

API Endpoints

/Single Uncles
/All Uncles


Our Blockchain endpoints found throughout the different On-Chain namespaces are available via REST API, WebSockets or JSON RPC. The list of supported Blockchain networks can be found in the API Documentation here.

Since we maintain our own nodes, we have every event from the genesis block forward which enables us to provide complete historical datasets for most chains we support.

Frequently Asked Questions

Does Ethereum still use uncles?

  • Uncles were a natural and expected part of Ethereum's previous Proof-of-Work (PoW) consensus mechanism, which was used to validate transactions and maintain the blockchain. As of September 15, 2022, Ethereum is now Proof-of-Stake (PoS) which does not use uncles in the same way as PoW. While highly unlikely, if uncles still appear they can be tracked using the endpoints above.

Do all blockchain networks use uncles?

  • No, not all blockchain networks use uncles. Uncles are specific to blockchain networks that use a proof-of-work consensus mechanism.

Are uncles included in the total number of blocks in a blockchain?

  • Yes, uncles are included in the total number of blocks in a blockchain, although they are not part of the main blockchain.