Zcash Activates NU7 Testnet Upgrade, Cutting Block Times to 25 Seconds

Zcash has activated its NU7 network upgrade on the public testnet, bringing the privacy-focused blockchain closer to a major mainnet upgrade.

NU7 reduces Zcash's target block time from 75 seconds to 25 seconds. The change is designed to make payments and deposits confirm faster while giving developers and infrastructure providers a live environment to test the new rules.

The upgrade activated at block 4,465,026 on October 4, ahead of the previously expected October 6 milestone.

The move comes as Zcash sees growing interest in privacy-focused crypto, including new regulated investment products and broader access through cross-chain integrations.

Zcash Moves to 25-Second Blocks

The biggest change in NU7 is faster block production.

Zcash currently targets one block every 75 seconds. NU7 cuts that target to 25 seconds, which could reduce the waiting time for payments, exchange deposits and other transactions.

For users who wait for multiple confirmations, the difference could be significant. Three confirmations under the new target would take about 75 seconds, compared with roughly 225 seconds under the current target, although actual block times can vary.

The faster blocks do not mean Zcash will create three times as many coins.

NU7 adjusts the block reward alongside the shorter block interval to preserve Zcash's existing issuance schedule. The network will continue to operate with its 21 million ZEC maximum supply.

Privacy Capacity Gets an Upgrade Too

NU7 also changes how shielded transactions are handled.

Shielded transactions allow Zcash users to keep details such as the sender, recipient and amount private while still allowing the network to verify the transaction.

The upgrade introduces limits on shielded actions within each block. These limits are designed to increase shielded transaction capacity while controlling the amount of work that wallets and nodes may need to perform.

The Zcash Foundation said the changes can more than double Orchard protocol throughput while reducing the worst-case synchronization load that spam activity could place on lightweight wallets.

That matters because faster blocks alone would not solve the network's scaling challenges. NU7 attempts to increase transaction speed while keeping the additional verification burden under control.

NU7 Also Changes Zcash's Fee System

Another major change is the Network Sustainability Mechanism, which changes how transaction fees are handled.

Under NU7, 60% of transaction fees will go into a reserve for future mining rewards, while miners receive the remaining 40%.

The mechanism is designed to help support mining as Zcash's scheduled block rewards decline over time. The reserve does not increase Zcash's maximum supply because the funds are removed from circulation before any future reissuance.

NU7 also disables version 4 transactions, which are associated with Zcash's older Sprout privacy system.

That means users with funds remaining in Sprout addresses will need to move those funds before the mainnet upgrade if they want to continue spending them through the network.

Mainnet Could Follow in November

NU7 is not yet active on Zcash mainnet.

Developers plan to review the testnet results on October 20 before deciding whether to proceed with the mainnet rollout. November 5 is currently the target date, but the final activation height has not been set.

The testnet period is therefore important for exchanges, wallets, miners and other infrastructure providers.

The Zcash Foundation has already released a NU7-compatible Zebra version so operators can test the new consensus rules before they reach the live network.

Institutional Access Is Growing

The technical upgrade arrives as Zcash gains more access to traditional investment markets.

Grayscale's Zcash ETF, ZCSH, launched on NYSE Arca on August 25. The fund reported more than $500 million in assets under management less than two weeks after launch, including more than $70 million in cumulative inflows during its first two weeks.

Zcash has also gained additional exchange-traded products in Europe, giving investors more ways to gain exposure to ZEC without directly holding the cryptocurrency.

This growing investment access is adding an institutional angle to Zcash's recent market activity.

Altcoin Buzz recently covered the same trend in Zcash Surges as Bitcoin Slips, Fueling a New Privacy Rotation, which looked at rising shielded activity, institutional access and the broader privacy narrative around ZEC.

Zcash Is Becoming Easier to Access Across Chains

Zcash's privacy features are also becoming more accessible through cross-chain infrastructure.

NEAR Intents currently lists ZODL, a privacy-focused Zcash wallet, as a live integration. It uses NEAR Intents to provide access to more than 30 chains and over 100 assets while allowing users to interact with Zcash's privacy features.

This matters because privacy features are only useful if users can easily access them.

Cross-chain integrations can make it easier for users holding assets on other networks to move into ZEC and then use Zcash's shielded ecosystem.

Zcash's Upgrade and Market Momentum Converge

NU7 gives Zcash a major technical catalyst at a time when the network is also gaining more market access.

The upgrade targets faster confirmations, greater shielded transaction capacity and a longer-term mechanism for supporting miners.

At the same time, Zcash has gained new regulated investment products and broader cross-chain access.

That combination is helping strengthen the privacy narrative around ZEC.

The immediate focus, however, remains on the NU7 testnet. Developers must first evaluate how the new rules perform before choosing a final mainnet activation height.

If testing goes as planned, Zcash could move to 25-second blocks on mainnet in November.

For now, NU7 marks an important step toward making Zcash faster while keeping its core privacy features at the center of the network.