Ethereum to Sunset Holešky Testnet Following Fusaka Upgrade

The Ethereum Foundation has announced the imminent shutdown of the Holešky testnet, marking the end of its operational lifecycle. This decision comes in the wake of the Fusaka upgrade, with the majority of remaining validator nodes set to be deactivated two weeks post-upgrade finalization, according to Ethereum’s official blog.

Background

Launched in 2023, Holešky was Ethereum’s largest public testnet, specifically designed for testing staking infrastructure and validator operations. The network played a crucial role in enabling validators to test significant protocol upgrades, including the Dencun and Pectra upgrades.

Despite its initial success, Holešky encountered significant challenges following the activation of the Pectra testnet in early 2025. Extensive inactivity leaks led to a prolonged exit queue, rendering the network impractical for testing the full validator lifecycle within reasonable timeframes. This situation necessitated the creation of the Hoodi testnet, launched in March 2025, to provide a more efficient testing environment.

Migration Path

With Holešky’s closure, Ethereum’s infrastructure providers and staking operators are encouraged to transition to the Hoodi testnet. Hoodi, developed to overcome Holešky’s limitations, offers a fresh validator set and supports all Pectra features. It is also poised to activate future protocol upgrades, including the forthcoming Fusaka fork.

Meanwhile, application and tooling developers previously utilizing Holešky are advised to migrate to Sepolia, Ethereum’s recommended testnet for smart contract and decentralized application (dApp) testing.

Current Testnet Landscape

Following Holešky’s decommissioning, Ethereum’s testnet ecosystem will comprise:

• Sepolia: For application and tooling development.
• Hoodi: For validator and staking provider testing.
• Ephemery: For lightweight validator lifecycle testing, resetting every 28 days.

Looking Forward

Holešky has provided valuable insights into large-scale validator operations, significantly informing the design of Hoodi and broader protocol testing practices. These learnings are expected to enhance Ethereum’s infrastructure and support future innovations in blockchain technology.

The Ethereum Foundation extends its gratitude to all contributors involved in running and maintaining Holešky throughout its operational period.

Image source: Shutterstock