Zcash has begun testing its NU7 network upgrade on the public testnet, activating the changes at block 4,465,026. The upgrade reduces the target block interval from 75 seconds to 25 seconds, meaning blocks are intended to arrive three times faster. For services requiring three confirmations, the theoretical wait would decline to around 75 seconds from 225 seconds. The change, however, remains confined to the testnet for now.
The test uses valueless testnet coins so developers, node operators and infrastructure providers can evaluate the upgrade before it affects real ZEC. NU7 includes several other protocol changes, including directing 60% of transaction fees to a future-reward reserve and cutting the per-block reward to one-third while maintaining the intended ZEC issuance schedule. Sprout transactions will also be disabled.
ZEC/USD has fallen 2.5% over the past 24 hours and is trading slightly above $1,300. Despite the recent pullback, the privacy-focused token remains more than 30% higher over the past 30 days, putting it among the better-performing crypto assets through September.
Why 25-Second Blocks Matter
The public testnet activation comes ahead of NU7’s planned November rollout. The upgrade is designed to move Zcash from its current 75-second target to 25-second blocks, potentially reducing the time between transaction batches.
Under an unchanged three-confirmation requirement, the estimated confirmation period would drop from 225 seconds to roughly 75 seconds. Actual timing can differ because block production varies, while exchanges, wallets and other providers can impose their own confirmation requirements before making deposits available.
The shorter block interval is only one component of NU7. Once the new rules take effect, miners will receive 40% of transaction fees, with the remaining 60% going toward the future-reward reserve. The block reward will also be reduced to one-third.
Another major change is the removal of Sprout transactions, Zcash’s oldest privacy system. Holders using Sprout will need to transfer their funds before the mainnet upgrade if they want to preserve their ability to spend them.
These changes mean NU7 is more than a straightforward speed upgrade. While faster blocks could help reduce waiting times for merchants accepting Zcash and exchanges processing deposits, service-specific confirmation rules will still determine when transactions become usable.
Three confirmations are not a universal requirement and should not be treated as a guaranteed measure of finality. The testnet provides a setting where infrastructure operators can assess these operational issues using coins that have no monetary value.
Zakura released its implementation on October 1, followed by the Zcash Foundation’s test release of Zebra on October 2. Both major node implementations now support the NU7 trial, allowing operators to test whether their infrastructure is ready for the updated protocol.
The testing phase is intended to verify more than block production speed. It gives developers and service providers an opportunity to check software compatibility, network behavior and their own confirmation policies before the changes potentially reach the mainnet.
October Review Ahead of November 5 Target
Developers plan to evaluate the testnet results on October 20 and use that review to determine whether the upgrade is ready for mainnet activation. November 5 remains the target date, although no mainnet activation block has been specified.
The current testnet launch does not guarantee a November 5 mainnet deployment. If NU7 moves forward, the practical effect on Zcash transactions will depend on network performance, compatible software adoption and the confirmation thresholds selected by individual services.
The roughly 75-second estimate for three confirmations assumes providers keep their existing policy. It therefore represents a potential reduction in waiting time rather than a promise that every Zcash deposit will be credited within 75 seconds.
