Inside Cardano's 'Van Rossum' hard fork, and what it means for users

Cardano activated its Van Rossem hard fork on July 18, 2026, upgrading the network to protocol version 11. This hard fork lowers the costs of executing smart contracts on Cardano by enhancing Plutus, the smart contract platform, and unifies built-in functions across its versions. It also tightens ledger validation rules, such as preventing stake pools from reusing cryptographic identity keys. Importantly, this upgrade prepares Cardano for a future large-scale scalability update known as Ouroboros Leios, expected in 2026, which aims to increase transaction throughput without compromising security.

A major significance of the Van Rossem hard fork is that it is the first in Cardano's history to be entirely proposed, debated, and ratified through the blockchain’s onchain governance system rather than being controlled by the founding developer, Input Output (IO). This governance process required approval from three distinct bodies: delegated representatives voted 78.97% in favor, the constitutional committee unanimously found it compliant, and stake pool operators narrowly approved it at 53.02%. Moreover, over 93% of block production switched to the new version before activation, surpassing the required 85% threshold.

For regular ADA holders, the upgrade does not change how basic transactions work, and wallet software does not require updates. Transaction fees remain the same for simple transfers. The main benefits will come in decentralized applications built on Cardano that can leverage cheaper and more capable smart contracts, potentially reducing user fees if developers update their contracts accordingly. The more profound effect lies in Cardano’s governance: the network has demonstrated it can now upgrade itself through stakeholder votes without directives from its original creators, marking a notable shift in control of protocol changes.

The Van Rossem hard fork is named in memory of Max van Rossem, a contributor to Cardano’s governance framework who passed away in October 2025. While the user-visible impacts are minimal now, the upgrade establishes critical technical and procedural foundations for future improvements, especially the anticipated Ouroboros Leios scaling solution, which aims to enhance transaction speed and network capacity. This combination of technical progress and decentralized governance represents a significant milestone in Cardano’s evolution.