SKN | Zcash Activates NU7 on Testnet Ahead of November Mainnet Target

Key Points

• Zcash has activated its NU7 network upgrade on testnet, allowing developers to evaluate the protocol changes under live conditions.
• NU7 is designed to reduce Zcash’s target block interval from 75 seconds to 25 seconds while introducing additional changes to transactions and network sustainability.
• Developers are scheduled to make a final mainnet decision on Oct. 20, with activation currently targeted for Nov. 5.

Zcash has activated its NU7 network upgrade on testnet, moving one of the network’s most significant planned protocol changes into live testing ahead of a targeted November mainnet rollout.

According to the Zcash testnet block explorer ZecBlock, block 4,465,026, designated as NU7’s activation point, was mined on Oct. 4 at 18:21:45 UTC. Zcash subsequently confirmed that the upgrade was live on testnet.

The testnet activation gives developers and node operators several weeks to evaluate the changes under real network conditions before deciding whether the upgrade is ready for mainnet deployment.

Faster Blocks Under NU7

One of the central changes introduced by NU7 is a reduction in Zcash’s target block spacing from 75 seconds to 25 seconds.

Shorter block intervals are intended to allow transactions to be confirmed more frequently, changing the pace at which the network processes blocks. The upgrade also disables version 4 transactions and incorporates a Network Sustainability Mechanism that redirects a portion of transaction fees toward future block rewards.

These changes affect both network performance and the economics of Zcash’s long-term protocol development.

The testnet period is therefore particularly important because developers can observe how the changes interact under actual network conditions before committing to the mainnet activation schedule.

Legacy Sprout Funds Face a Deadline

NU7 also introduces an important consideration for users holding ZEC in Zcash’s legacy Sprout shielded pool.

Because version 4 transactions will be disabled, ZEC remaining in the legacy Sprout pool could become unspendable once NU7 is fully activated. Users holding affected funds therefore need to move them before the upgrade reaches mainnet activation.

The change makes the testnet phase relevant not only to developers and node operators but also to users who may need to take action before the mainnet transition.

Developers Begin Real-World Testing

The Zcash Foundation has encouraged testnet operators to run the NU7 release candidate and evaluate the upgrade under real operating conditions.

Testing is intended to identify potential issues before the network moves to mainnet. Developers will use their experience during this phase to determine whether the planned protocol changes are ready for deployment or whether additional work is required.

The process also provides an opportunity to evaluate the network’s behavior with the shorter block interval and other protocol modifications operating together rather than in isolated testing environments.

Mainnet Decision Set for October

Zcash developers are scheduled to make a final decision on whether to proceed with the NU7 mainnet activation on Oct. 20. The decision will be based on the results of the testnet period, with developers also expected to establish the precise activation height at that time.

The current target for mainnet activation is Nov. 5.

That timeline gives the network several weeks between the testnet activation and the planned mainnet rollout. Any significant issues identified during testing could therefore influence the final decision or activation schedule.

Outlook

NU7 represents a substantial change to Zcash’s network operation, particularly through its planned reduction of block spacing from 75 seconds to 25 seconds and its changes to transaction and reward mechanisms.

The testnet activation now gives developers a defined window to evaluate those changes under live conditions. The Oct. 20 decision will be the next major milestone, while the Nov. 5 target will depend on whether testing demonstrates that the upgrade can proceed without material issues.