Privacy-focused cryptocurrency Zcash has officially taken a major step toward its next protocol evolution by activating the NU7 network upgrade on its testnet. This milestone successfully moves the highly anticipated code changes into a live, public testing environment roughly a month before developers plan to deploy the upgrade to the mainnet.
According to data from the Zcash testnet block explorer ZecBlock, block 4,465,026—which served as the designated activation point for the NU7 upgrade—was successfully mined on Oct. 4 at 18:21:45 UTC. Shortly after the block was recorded on the ledger, project leadership and core developers took to social media to confirm the milestone. Zcash officially verified the deployment in a post on X, informing the broader community and ecosystem participants that NU7 was officially live and operational on the testnet.
The NU7 upgrade represents a comprehensive set of improvements for the Zcash network, introducing several foundational changes aimed at enhancing performance, transaction mechanics, and long-term economic sustainability. Among the most prominent modifications is a dramatic acceleration of block production times. The upgrade seeks to reduce the network’s target block spacing from the current 75 seconds down to just 25 seconds, a change that will significantly speed up transaction confirmation times for users.
In addition to faster blocks, NU7 introduces critical technical and economic updates. The upgrade disables version 4 transactions entirely, removing legacy transaction formats from the protocol. Furthermore, it integrates a newly designed Network Sustainability Mechanism. This feature is engineered to automatically redirect a portion of transaction fees into future block rewards, introducing a novel structural adjustment to the way network incentives and long-term security funding are managed.
The deprecation of version 4 transactions, however, carries profound implications for users holding native ZEC tokens in older storage configurations. Specifically, any funds currently held within Zcash’s legacy Sprout shielded pool will become entirely unspendable once the upgrade goes into full effect. Because the legacy pool is being phased out through the removal of version 4 transaction support, users holding assets in these older shielded addresses must proactively move their funds to modern pools before NU7 fully activates to avoid losing access to their assets.
Following the successful testnet deployment, the Zcash Foundation released a statement on Friday advising testnet operators, node runners, and ecosystem developers to utilize the newly issued release candidate to rigorously test NU7 under real-world conditions. This crucial testing phase is designed to give developers, miners, and wallet providers ample opportunity to observe how the upgraded software performs, identify any potential bugs or unforeseen friction points, and assess overall network stability before committing to a mainnet release.
The data and operational insights gathered during this testnet phase will directly inform the final deployment schedule. Zcash developers are officially scheduled to make a final, binding decision on mainnet activation during a governance and technical review on Oct. 20. During this meeting, developers will evaluate the stability of the testnet implementation and, if everything proceeds as planned, set the exact activation block height for the mainnet rollout.
Presently, the target date for the mainnet activation of NU7 is scheduled for Nov. 5, pending successful results from the ongoing testnet evaluation period. As the development teams, node operators, and community stakeholders monitor the performance of the testnet over the coming weeks, attention will remain focused on ensuring a smooth transition that minimizes disruptions while ushering in faster transaction times and the new economic mechanisms embedded within the NU7 protocol.
