Ethereum Holesky testnet, the biggest among the lot, will shut down later this year, closing a two-year chapter in large-scale network testing. The decommissioning will occur roughly two weeks after the Fusaka upgrade is finalized, at which point client and infrastructure teams will withdraw their support.
When Scale Becomes a Bottleneck
Holesky was launched in 2023 to pressure-test Ethereum’s proof-of-stake system. It quickly grew into the largest public testnet and became the launchpad for major upgrades such as Dencun and Pectra. But its very scale created hurdles. After Pectra, inactivity from offline validators caused severe backlogs, with validator exits stretching into months, making Holesky less practical for developers who need quick results.
Hoodi Steps In
To provide a cleaner slate, Ethereum introduced the Hoodi testnet in March 2025. Hoodi carries forward Holesky’s role in validator and staking provider testing, but without the structural challenges that slowed its predecessor.
A Network of Testnets
Even as Holesky winds down, Ethereum’s testing ecosystem remains diverse. Sepolia continues to anchor dapp and smart contract trials, while Ephemery provides short, resettable validator cycles every 28 days.
The retirement of Holesky signals Ethereum’s shift toward more specialised test environments. Instead of relying on a single large staging ground, developers will now have multiple testnets tailored to specific use cases. This evolution reflects Ethereum’s broader push for scalability and efficiency, ensuring that upgrades can be tested and deployed with fewer bottlenecks as the network continues to mature.
FAQs
What is the Holesky testnet?
Holesky is Ethereum’s largest public testnet, launched in 2023 to stress-test the network’s proof-of-stake system. It served as a staging ground for major upgrades like Dencun and Pectra, allowing developers and infrastructure teams to experiment at scale before pushing changes to mainnet.
How big is the Holesky testnet?
Holesky quickly became the largest Ethereum testnet, with validator counts surpassing those on mainnet. Its scale made it ideal for testing staking infrastructure and validator operations, though this also created bottlenecks — such as month-long validator exits caused by inactive nodes.
What is Ethereum Holesky RPC?
The Ethereum Holesky RPC (Remote Procedure Call) endpoint allows developers to connect their applications and tools to the Holesky testnet. Through RPC URLs, dapps can query blockchain data, simulate transactions, and test staking or validator workflows without risking real assets.
