Cardano activates van Rossem hard fork, paving way for Leios
Cardano activated its van Rossem hard fork on Saturday, upgrading mainnet to version 11. The change is expected to reduce smart contract execution costs and prepare the network for Ouroboros Leios, a major scalability upgrade. Onchain data shows the protocol moved from version 10 in epoch 643 to version 11 in epoch 644. Input Output said the upgrade includes Plutus improvements and cost model enhancements, and also sets up the next Dijkstra era hard fork, which will introduce Ouroboros Leios. Leios is a scaling proposal for Cardano’s proof-of-stake consensus that aims to greatly increase transactions per second while preserving security, with launch targeted for late 2026. This is also Cardano’s first governance-driven hard fork, rather than one coordinated by Input Output.
