Zcash hits the fast lane: devs flip 75-second blocks to 25 on Nov. 5 ⏩

Zcash developers are targeting Nov. 5 to activate the NU7 network upgrade, cutting the protocol's target block spacing from 75 seconds to 25 seconds after Zcash development organizations and engineering teams reached "unanimous agreement" on the scope and timeline. Developer Sean Bowe said on Thursday that the upgrade is scheduled to activate on the Zcash testnet on Oct. 6, with a final decision on the mainnet activation height set for Oct. 20 following testnet performance review. Code for the planned features is targeted for completion by Sept. 30.

The upgrade will disable version 4 transactions and integrate the Network Sustainability Mechanism (NSM), with the chosen NSM configuration preserving Zcash's halving schedule. The reintroduction of previously removed supply will begin in February 2031, a date the five development teams described as the most conservative reading of a coinholder vote. Bowe said NU7 would not introduce new transaction formats and should not significantly affect wallets, though full nodes, indexers and block explorers may require adjustments.

A Wednesday coinholder vote showed overwhelming support for the proposals: 98.9% backed keeping halvings, while 99.9% of the ZEC-weighted vote supported the faster-block proposal, with 2.4 million ZEC voted by 66% of the eligible pool. The participating organizations include the Zcash Foundation, Project Tachyon, Valar Group, ZODL and Shielded Labs.

To offset the threefold increase in blocks per day, the ZIP 218 proposal divides the per-block reward by roughly three, keeping total issuance per unit of wall-clock time unchanged. The NSM will set aside roughly 60% of transaction fees rather than letting them disappear, with those banked fees flowing back as supplemental mining rewards starting in February 2031. None of the changes alter day-to-day wallet use, and NU7 does not add new transaction types.

The timeline follows a sharp run for ZEC, which rose about 20% over 24 hours on Thursday to a new high above $1,526 as privacy coins substantially outperformed the wider market. Glassnode data showed the privacy-coin sector was 213% above its level at Bitcoin's October 2025 peak, while a basket excluding ZEC was up about 85% over the past year. ZEC is up over 2,500% in the past year, a recovery from July's Ironwood upgrade that patched a four-year-old flaw that could have let someone mint counterfeit ZEC and briefly sent the token down 38%.