Cardano’s blockchain has undergone a landmark upgrade that, for the first time in its history, was approved entirely by its community rather than by the company that created it.
The “Van Rossem” hard fork – activated on Saturday and moving Cardano’s mainnet to protocol version 11 – both cuts the cost of running smart contracts and lays the technical foundations for a major scaling overhaul expected later in 2026.
But its most far-reaching impact is political rather than technical. The upgrade is the first to be initiated, debated and ratified through Cardano’s on-chain governance system, instead of being driven by Input Output, the engineering firm that originally designed and built the network.
Previously, every hard fork on Cardano was organised from the top down by its founding entities. Van Rossem instead was passed under the framework introduced in Cardano’s so‐called “Voltaire” era, which allows stakeholders to vote directly on protocol changes.
How the vote was won
On-chain data from Cardanoscan shows the network transitioned from version 10 in epoch 643 to version 11 in epoch 644, with the hard fork taking effect on Saturday 18 July at 21:44 UTC, following formal ratification on 13 July.
Approval required support from three separate groups, each with a distinct role under Cardano’s constitution.
Delegated representatives – individuals or organisations chosen by ADA holders to vote on proposals on their behalf, in a structure likened to a parliamentary system – backed the upgrade by 78.97%, comfortably above the 60% threshold.
The constitutional committee, an elected body charged only with checking whether proposals comply with the Cardano Constitution rather than judging their technical merits, unanimously ruled the hard fork was compliant. All seven members supported it, where five votes were required.
By contrast, stake pool operators – who actually run the infrastructure that produces blocks on the network – offered more hesitant backing. Just 53.02% voted in favour, the narrowest margin of the three groups and a reminder, supporters say, that decentralised governance does not guarantee the founders’ preferred outcome.
Under the constitutional rules, at least 85% of active stake by pools had to be running compatible node software ahead of ratification. Telemetry from the network indicated adoption was well ahead of that mark, with about 93% of block production already on version 11 before activation.
Technical changes and Plutus upgrade
From a technical perspective, version 11 is described as an “intra-era” hard fork. It stays within Cardano’s current governance-focused era and does not alter the transaction structure, meaning minimal disruption for most users and infrastructure providers.
The upgrade extends the capabilities of Plutus, the smart contract platform used by developers on Cardano. It standardises the built‐in functions across Plutus’s three versions so that older applications can access newer features without being completely rewritten.
It also tightens a number of ledger validation rules, including a new guarantee that two stake pools cannot share the same cryptographic identity key – a measure aimed at strengthening the protocol’s operational security.
“As well as Plutus improvements and Plutus Cost Model enhancements, this upgrade lays the foundation for the next upgrade, the Dijkstra era hard fork, which will introduce Ouroboros Leios to Cardano,” Input Output wrote in a development report on Friday.
Ouroboros Leios is a scaling proposal for Cardano’s proof‐of‐stake consensus system. Scheduled for later in 2026, it is intended to significantly increase the number of transactions the network can process each second while maintaining its security guarantees.
What users will notice – and what comes next
For everyday ADA holders, the immediate impact of Van Rossem is deliberately limited. Wallets do not require updating, transaction fees for sending ADA are unchanged and the basic experience of using the network is the same.
The main benefits are expected to emerge through the applications built on top of Cardano. The Plutus changes reduce the computational cost of running smart contracts – the code powering decentralised finance (DeFi) platforms, NFT marketplaces and other on‐chain services.
Because users pay a fee each time they interact with such applications, and part of that charge reflects how much computation the contract demands, cheaper execution should allow developers to lower per‐transaction costs. However, those savings will only be realised if developers update or rebuild their contracts to exploit the new cost model.
Longer term, supporters of the governance shift argue the more fundamental change is over who decides the network’s future direction. On many blockchains, a founding company or core team sets the roadmap, leaving users with little formal influence.
By passing Van Rossem via on‐chain vote, Cardano holders have demonstrated they can authorise protocol changes themselves. For investors in ADA, advocates say that is the distinction between holding a token on a network guided by a central team and having a defined role in steering its development.
The Van Rossem hard fork is also seen as procedural groundwork for Ouroboros Leios, both in terms of the ledger changes it introduces and the precedent it sets for future community‐ratified upgrades.
A tribute in name
The hard fork is named after Max van Rossem, a Cardano governance contributor who played a role in shaping the network’s constitution and who died in October 2025.
While the upgrade itself may be largely invisible to casual users, its backers argue that, combined with the forthcoming Dijkstra era and Ouroboros Leios, it marks the start of a new phase in which Cardano can both scale and evolve under direct control of its stakeholders rather than its original creators.
