Zcash activates NU7 network upgrade on testnet at block height 4,465,026

Zcash has switched on its NU7 network upgrade on the public testnet at block height 4,465,026. It is the first live environment where the privacy coin’s biggest protocol overhaul in years can actually be exercised. The changes are substantial. NU7 aims to cut block times from 75 seconds to 25 seconds, introduce a fee-recycling system and retire one of Zcash’s oldest shielded transaction formats. What NU7 actually changes The upgrade ships through Zebra 7.0.0-rc.0, a release candidate of the Zebra node software released on October 2, 2026. Testnet activation was expected around October 6, 2026. The headline feature is speed. ZIP 218 changes block spacing, bringing the target block time down to 25 seconds from the previous 75 seconds. The second major piece is the Network Sustainability Mechanism, or NSM. Under the upgrade, the NSM directs 60% of transaction fees toward supporting the network’s longevity. Two proposals, ZIP 235 and ZIP 237, govern how the NSM functions. The third change is a cleanup. NU7 retires the Sprout shielded pool, which disables v4 transactions. The upgrade also introduces no new transaction formats. Testnet quirks and the road to mainnet The testnet runs with...