Ethereum Shuts Down Largest Testnet Holesky Following Fusaka Upgrade

Ethereum's infrastructure just got leaner—and developers are scrambling.

The Fusaka upgrade triggered the immediate sunset of Holesky, Ethereum's largest and most critical testnet. This isn't just routine maintenance—it's a strategic consolidation.

Holesky served as the primary staging ground for major protocol upgrades, stress-testing Ethereum's scalability and validator performance under near-mainnet conditions. Its closure signals confidence in Ethereum's post-upgrade stability.

Developers now pivot to remaining testnets, but the absence of Holesky's scale means future testing might carry higher risks—or higher costs, because nothing says 'progress' like quietly offloading operational risk onto the mainnet. On-chain, the merge concludes another chapter in Ethereum's relentless evolution.