What to Know

  • Zcash activated its NU7 upgrade on a public test network, moving the protocol into a live rehearsal phase before a planned mainnet rollout.
  • NU7 cuts the targeted block time from 75 seconds to 25 seconds, a change designed to reduce waiting time between batches of transactions.
  • The upgrade went live at block 4,465,026, with Zakura listing the new rules as active on public testnet.
  • The planned mainnet rollout remains targeted for Nov. 5, though no mainnet activation block has been set yet.
  • Developers plan to review test results and decide on mainnet activation Oct. 20.
  • NU7 redirects 60% of transaction fees to a reserve intended to fund future mining rewards, while miners receive 40% of transaction fees.
  • The per-block reward is reduced to one-third so faster block production does not accelerate ZEC’s issuance schedule.
  • The upgrade disables transactions using Sprout, Zcash’s oldest private-payment system, requiring holders with funds there to move them before mainnet activation if they want to retain access through the existing system.
  • Both major node programs now support the trial, with Zakura releasing its implementation Oct. 1 and the Zcash Foundation publishing a test version of Zebra the following day.

Zcash Starts Public Trial of Faster Blocks

Zcash has activated its NU7 upgrade on a public test network, introducing a major timing change that cuts the targeted interval between blocks from 75 seconds to 25 seconds. The move gives exchanges, wallets, miners, developers and other infrastructure operators a live testing environment before a planned mainnet rollout targeted for Nov. 5.

The upgrade switched on at block 4,465,026. Zakura, software that follows Zcash and checks its transactions, now lists the NU7 rules as active on public testnet. The separate testing network used earlier in the process has been shut down, shifting attention to the public test environment where operators can observe how the new rules behave under broader use.

The change is significant because blocks are the basic units in which Zcash transactions are grouped and confirmed. By reducing the target time between blocks, NU7 aims to shorten the wait between transaction batches. In practical terms, this could affect how quickly a merchant views a payment as sufficiently settled or how soon an exchange credits a deposit after a user sends funds.

Why the 25-Second Target Matters

Under the current target, Zcash blocks are expected every 75 seconds. NU7 reduces that target to 25 seconds, meaning the protocol is designed to produce blocks more frequently. If a service keeps the same confirmation policy, faster blocks can reduce the targeted waiting period before a transaction is treated as final enough for that service’s internal rules.

For example, a service waiting for three confirmations would face a targeted wait of about 75 seconds instead of 225 seconds if it did not change its confirmation requirement. That comparison illustrates the user-facing effect of the block-time reduction, though actual block times can vary. Market participants typically watch these changes closely because confirmation speed influences the experience of payments, deposits and withdrawals across the ecosystem.

Faster blocks do not automatically solve every operational challenge. Exchanges and wallets still have to decide how many confirmations they require, how they manage risk and how quickly they credit deposits. However, the public testnet activation gives these operators a chance to measure the new cadence, adjust systems and identify issues before real ZEC is affected on mainnet.

Testnet Gives Infrastructure Operators a Rehearsal

The public test network uses coins with no monetary value, making it a controlled environment for experimenting with the upgrade. Developers and infrastructure teams can use it to check whether their software follows the new rules, handles faster block production and processes transactions correctly under the upgraded conditions.

Both major node programs now support the trial. Zakura released its NU7 implementation Oct. 1, and the Zcash Foundation published a test version of Zebra the following day. Operators need compatible software to follow the upgraded public testnet, which makes the current phase especially important for technical readiness.

For exchanges and wallet providers, protocol upgrades require careful preparation. Systems that track deposits, confirmations, balances and withdrawals need to remain aligned with consensus rules. A public test phase helps reduce the risk of disruption by giving service providers time to upgrade, monitor and validate their infrastructure before mainnet activation is considered.

Fee Routing Changes Under NU7

NU7 also changes how transaction fees are handled. Under the upgrade, miners receive 40% of transaction fees. The remaining 60% is removed from circulation and recorded in a reserve intended to fund future mining rewards. That reserve is designed to support payments to miners as the amount of newly issued ZEC declines over time.

This fee-routing mechanism is part of a broader adjustment to the network’s incentive structure. Miners play a key role by checking transactions and helping secure the chain. As newly issued ZEC declines according to the issuance schedule, protocol designers have to consider how future rewards can continue to support the work required to maintain the network.

The reserve approach does not mean all transaction fees are immediately paid out to miners. Instead, a portion is set aside for future mining rewards. For market observers, this element of NU7 is important because it touches both network security and long-term economic design, two areas that can shape confidence in a blockchain’s durability.

Faster Blocks Without Faster Issuance

One of the most important economic details in NU7 is that faster blocks are not intended to triple new coin creation. Because the target block time drops from 75 seconds to 25 seconds, the protocol must adjust rewards to preserve the issuance schedule. NU7 does this by reducing the scheduled reward per block to one-third.

That adjustment means the network can produce blocks more frequently while maintaining the planned pace of ZEC issuance. Without such a change, faster block production could have altered the supply trajectory. By cutting the per-block reward to one-third, NU7 keeps the issuance schedule intact even as the transaction confirmation rhythm changes.

For traders and long-term holders, supply rules are often as important as performance improvements. A faster transaction experience can be constructive for usability, but changes that unexpectedly affect issuance may raise concerns. NU7’s reward adjustment is meant to separate the speed upgrade from the supply schedule, preserving the monetary framework while improving block cadence.

Sprout Transactions Set to Be Disabled

NU7 also disables transactions using Sprout, Zcash’s oldest private-payment system. This is a critical operational point for holders who still have funds in Sprout. Those users would need to move their funds before mainnet activation if they want to retain the ability to spend them through the existing system.

The Sprout change reflects the broader challenge of maintaining legacy privacy infrastructure while continuing protocol development. Older systems can create complexity for wallets, node software and network maintenance. Disabling Sprout transactions under NU7 narrows the supported transaction set, but it also places responsibility on affected holders to act before the upgrade reaches mainnet.

Because the mainnet rollout has not yet occurred, the public test phase provides time for communication and preparation. Wallet providers and other service operators may need to alert users, review support for affected funds and ensure that migration steps are understood. The key date for the decision process is Oct. 20, when developers plan to review test results and decide on mainnet activation.

Mainnet Decision Still Pending

Although the public testnet upgrade is active, mainnet activation is not final. Developers plan to review the test results and make a decision on Oct. 20. Nov. 5 remains the target for mainnet rollout, but no mainnet activation block has been set yet.

This distinction matters. Testnet activation shows that the upgrade has entered a practical trial stage, but it does not guarantee that mainnet will activate on the target date. If the test phase exposes problems, the timeline could require reassessment. If the trial proceeds as expected, the network may move closer to the planned November launch.

For now, technical traders and crypto market participants are likely to view NU7 as a network development milestone rather than a completed mainnet change. The upgrade’s potential impact depends on successful testing, operator readiness and the final activation decision. Until then, the public testnet provides the clearest view of how 25-second Zcash blocks behave in a live setting.

What It Means for Zcash Users

For everyday users, the most visible effect of NU7 could be shorter waiting times where services keep their confirmation requirements unchanged. A payment or deposit that depends on multiple confirmations may move through the process more quickly under the new target block time. However, each service controls its own policies, and actual block production can vary from the target.

For developers, the upgrade introduces a period of implementation and monitoring. Software must follow the upgraded rules, and infrastructure must be tested against the new block cadence. For miners, NU7 changes both the per-block reward and the treatment of transaction fees, making the economic adjustment a central part of the upgrade.

For holders with funds in Sprout, the message is more direct: action is required before mainnet activation to retain access through the existing system. That makes the upcoming review period especially important, since the Oct. 20 decision will help determine whether the Nov. 5 target remains on track.

Frequently Asked Questions (FAQs)

What is Zcash NU7?

NU7 is a Zcash network upgrade that changes several protocol rules, including the target block time, fee routing, block rewards and support for Sprout transactions.

What changed on the Zcash public testnet?

Zcash activated NU7 on public testnet at block 4,465,026, cutting the target block time from 75 seconds to 25 seconds and enabling infrastructure operators to test the new rules.

When is the Zcash NU7 mainnet rollout planned?

The mainnet rollout is targeted for Nov. 5, though no mainnet activation block has been set yet. Developers plan to review test results and decide on activation Oct. 20.

Does a 25-second block target mean transactions are final in 25 seconds?

No. A 25-second target means blocks are designed to be produced more frequently, but actual block times vary and services may still require multiple confirmations before treating a transaction as complete.

How could NU7 affect exchange deposits?

If an exchange keeps the same confirmation requirement, faster blocks could reduce the targeted wait for deposits. A service waiting for three confirmations would face a targeted wait of about 75 seconds instead of 225 seconds.

Will faster blocks increase ZEC issuance?

NU7 is designed to preserve ZEC’s issuance schedule. The scheduled reward per block falls to one-third so that faster block production does not triple the creation of new coins.

How are transaction fees handled under NU7?

Under NU7, miners receive 40% of transaction fees, while 60% is removed from circulation and recorded in a reserve intended to fund future mining rewards.

What happens to Sprout transactions?

NU7 disables transactions using Sprout, Zcash’s oldest private-payment system. Holders with funds in Sprout need to move them before mainnet activation to retain access through the existing system.

Which node software supports the NU7 testnet trial?

Both major node programs support the trial. Zakura released its implementation Oct. 1, and the Zcash Foundation published a test version of Zebra the following day.