Dencun is a major Ethereum network upgrade that combines two coordinated sets of changes, Deneb for the consensus layer and Cancun for the execution layer. Together, they are designed to make Ethereum scale more effectively, especially for Layer 2 rollups, while improving overall network efficiency.
Deneb and Cancun, one upgrade across two layers
Ethereum is split into a consensus layer, which handles validator coordination and finality, and an execution layer, which runs transactions and smart contracts. Dencun upgrades both at once, which is why it is described as a fusion of Deneb and Cancun. This dual approach matters because many scaling improvements require coordinated changes across how blocks are proposed and how data and transactions are processed.
Proto-danksharding (EIP-4844) and cheaper rollups
The headline feature of Dencun is proto-danksharding, introduced via EIP-4844. It creates a new way for rollups to post data to Ethereum using temporary data “blobs,” rather than competing for the same scarce and expensive calldata space used by normal transactions. In practice, this helps reduce the cost of publishing rollup data on Ethereum, which can translate into lower fees for users interacting with Layer 2 networks such as optimistic rollups and zero-knowledge rollups. It is an important stepping stone toward full danksharding, a longer-term scaling goal on Ethereum’s roadmap.
Other EIPs and ecosystem impact
Dencun also bundles additional Ethereum Improvement Proposals, including EIP-4788, which improves how smart contracts can access beacon chain related information. These supporting changes enhance developer capabilities and help infrastructure providers build more robust tools.