Zcash Launches Major NU7 Upgrade on Testnet
Zcash has activated its NU7 network upgrade on the public testnet at block height 4,465,026, marking the first live environment where the privacy coin’s most significant protocol overhaul in years can be tested. The upgrade introduces substantial changes, including a reduction in block times from 75 seconds to 25 seconds, a fee-recycling system called the Network Sustainability Mechanism (NSM), and the retirement of the Sprout shielded transaction format.
The NU7 upgrade was implemented through Zebra 7.0.0-rc.0, a release candidate of the Zebra node software released on October 2, 2026. The testnet activation was expected around October 6, 2026. The upgrade aims to enhance network speed with ZIP 218, which reduces block spacing, and introduces the NSM, which directs 60% of transaction fees toward supporting the network’s longevity.
The testnet operates with specific parameters, including an adjusted third halving at block height 4,497,948, and NSM reissuance beginning at block height 7,305,222. The mainnet decision is scheduled for October 20, 2026, with a target activation date of November 5, 2026. Until then, mainnet operators do not need to take any action, as no activation height has been designated for the mainnet environment.
Several organizations, including the Zcash Foundation, Project Tachyon, Valar Group, ZODL, and Shielded Labs, collaborated on the upgrade. They reached a unanimous agreement on the upgrade’s scope after polling coinholders. For traders, the key dates are October 20, 2026, for the decision, and November 5, 2026, for the mainnet activation. Exchanges, wallet providers, and node operators will need to update their systems to accommodate the changes, particularly the retirement of the Sprout shielded pool and the disabling of v4 transactions.