Frequently Asked Questions

Zcash (ZEC) is a decentralized, open-source cryptocurrency that offers strong privacy protections. Launched in October 2016, it uses advanced cryptographic techniques, specifically zero-knowledge proofs, that allow transactions to be verified without revealing the sender, receiver, or amount.

Zcash has a fixed maximum supply of 21 million coins and uses a proof-of-work consensus mechanism. The key difference is that Zcash gives users the choice between transparent transactions (publicly visible on the blockchain) and shielded transactions (fully private).

A zero-knowledge proof (ZKP) is a cryptographic method that allows one party to prove a statement is true without revealing any information beyond the validity of the statement itself. In Zcash's context, ZKPs allow the network to verify that a transaction is valid (the sender has enough funds, no double-spending occurs) without learning who sent it, who received it, or how much was transferred.

Zcash uses a specific type of ZKP called a zk-SNARK (Zero-Knowledge Succinct Non-Interactive Argument of Knowledge). The "succinct" part means the proofs are small and quick to verify, even though the underlying computation is complex.

While Zcash shares much of its DNA with Bitcoin (same 21M supply cap, UTXO model, proof-of-work), there are several key differences:

• Privacy: Bitcoin transactions are fully transparent on the blockchain. Zcash offers both transparent and shielded transactions. Shielded transactions hide the sender, receiver, and amount using zero-knowledge proofs.
• Block time: Zcash targets a 75-second block time (since the Blossom upgrade), compared to Bitcoin's ~10-minute block time.
• Mining algorithm: Zcash uses Equihash, a memory-hard proof-of-work algorithm, rather than Bitcoin's SHA-256.
• Funding mechanism: A portion of each Zcash block reward is directed to development funds (currently Zcash Community Grants and a lockbox), whereas Bitcoin relies entirely on voluntary contributions for development.

A zatoshi is the smallest unit of Zcash, the smallest unit of Zcash. One ZEC equals 100,000,000 (10⁸) zatoshis. When you see very small ZEC amounts on the explorer (like transaction fees), they are often more naturally expressed in zatoshis. For example, a fee of 0.00001000 ZEC is 1,000 zatoshis.

Shielded transactions use zero-knowledge proofs to encrypt the sender address, receiver address, and transaction amount on the blockchain. Only the parties involved (and anyone they share a viewing key with) can see the details. To the rest of the network, the transaction appears as a valid transfer with no visible details.

On this explorer, you'll see shielded transactions labeled as "Shielded" or "Orchard" depending on which shielded pool they use. Their inputs and outputs appear as "Shielded Input" and "Shielded Output" placeholders since the actual values are encrypted.

In transparent transactions, the sender, receiver, and amount are all publicly visible on the blockchain. They use transparent addresses (starting with "t1" or "t3") and are fully auditable. On this explorer, these are labeled with the "Transparent" type badge.

A mixed transaction involves both transparent and shielded components, for example spending from a transparent address into a shielded pool, or vice versa. On this explorer, these are labeled "Mixed." While the transparent portions are visible, the shielded portions remain private. Mixed transactions are common when users move funds between transparent and shielded pools (sometimes called "shielding" or "deshielding" ZEC).

Zcash has several address types, each identified by its prefix:

• t1 (Transparent P2PKH): Pay-to-Public-Key-Hash. The most common transparent address type. Funds and transactions are fully visible on the blockchain.
• t3 (Transparent P2SH): Pay-to-Script-Hash. Supports more complex spending conditions like multi-signature wallets. Also fully transparent.
• zs (Sapling Shielded): Addresses in the Sapling shielded pool. Transactions using these addresses are fully private using zk-SNARKs.
• zc (Sprout Shielded): Addresses in the original Sprout shielded pool. This was the first generation of shielded addresses; Sapling and Orchard have since superseded it with better performance and security.
• u1 (Unified): Unified addresses bundle multiple receiver types (transparent + Sapling + Orchard) into a single address. The wallet automatically selects the best receiver type. This is the recommended address format for modern Zcash usage.

Zcash has multiple "value pools" that track where ZEC is held across different protocol layers. Each pool has different privacy and functionality characteristics:

• Transparent pool: ZEC held in transparent addresses (t1/t3). Balances and transactions are publicly visible.
• Sprout pool: The original shielded pool from Zcash's 2016 launch. Transactions are private but the cryptography is older and less efficient. Very little ZEC remains here.
• Sapling pool: Introduced in the 2018 Sapling upgrade. Significantly faster and more efficient shielded transactions compared to Sprout.
• Orchard pool: Introduced in the 2022 NU5 upgrade. Uses the Halo 2 proving system which eliminates the need for a trusted setup ceremony. This is the newest and most advanced shielded pool.

The "Value Pool Distribution" chart on the Dashboard tracks how ZEC is distributed across these pools over time. An increasing share in shielded pools (Sapling + Orchard) indicates growing privacy adoption.

A unified address (UA) is a single address string starting with "u1" that encodes multiple receiver types (typically transparent, Sapling, and Orchard receivers). When you send ZEC to a unified address, your wallet automatically picks the most private receiver type it supports.

Unified addresses simplify the user experience by removing the need to choose between address types. They also future-proof payments: as wallets upgrade to support newer shielded protocols, the same address automatically gets more private.

Zcash has a hard cap of 21 million ZEC. No more than 21,000,000 ZEC will ever exist. The circulating supply increases with each new block as mining rewards are issued, and gradually approaches the cap over the coming century. The emission curve chart on the Dashboard visualizes this, and you can see the supply approaching but never reaching 21M.

The block subsidy is the amount of newly created ZEC awarded with each block. It is the primary incentive for miners to secure the network. The subsidy halves approximately every 4 years (every 1,680,000 blocks post-Blossom).

The block subsidy is split between the miner and development funds. On block detail pages, you can see this breakdown: the miner subsidy, transaction fees, and the portions going to Zcash Community Grants (ZCG) and the Coinholder-Controlled Fund (CCF / Lockbox).

A halving is a scheduled event where the block subsidy is cut in half. Zcash halvings occur every 1,680,000 blocks (approximately every 4 years at the 75-second block time). This mechanism controls inflation and ensures the 21M supply cap is approached gradually.

Zcash halving history:

• 1st halving (Nov 2020, block 1,046,400): Reward dropped from 6.25 ZEC to 3.125 ZEC. This also marked the end of the original Founders' Reward.
• 2nd halving (Nov 2024, block 2,726,400): Reward dropped from 3.125 ZEC to 1.5625 ZEC. The NU6 upgrade introduced the Lockbox fund at this halving.
• 3rd halving (~Nov 2028, block 4,406,400): Projected. Reward will drop to ~0.78125 ZEC.

The "Next Halving" card on the Dashboard tracks the countdown to the next halving with a progress bar, estimated date, and the current vs. next block subsidy.

The emission curve describes how new ZEC enters circulation over time. It starts steeply (when block rewards are largest) and flattens as halvings reduce the issuance rate. The Dashboard features an interactive emission curve chart where you can hover over historical milestones to see how supply grew at each point.

Key milestones on the curve include the Genesis launch (Oct 2016), the Sapling and Blossom upgrades, each halving event, and the projected final emission around the year 2137.

For the first 20,000 blocks after Zcash's launch, the block reward linearly ramped from 0 ZEC up to 12.5 ZEC. This "slow start" mining period was designed to reduce the advantage of early miners and allow time for the network to stabilize. It lasted roughly 34 hours. After the slow start, the full 12.5 ZEC block reward took effect.

The Founders' Reward was a mechanism active during Zcash's first halving era (blocks 1 through 1,046,399). During this period, 20% of each block reward was distributed to Zcash founders, investors, employees, and advisors. The remaining 80% went to miners. The Founders' Reward ended at the first halving in November 2020 and was replaced by the development fund structure.

After the Founders' Reward ended, the Zcash community approved a development fund that allocates a portion of each block reward to support ongoing protocol development and ecosystem growth. The fund structure has evolved across network upgrades:

• Zcash Community Grants (ZCG): Funds independent development teams and community projects. On block detail pages, you can see the ZCG portion of each block reward.
• Coinholder-Controlled Fund (CCF / Lockbox): Introduced at the 2nd halving with the NU6 upgrade. These funds are locked on-chain and cannot be spent until a future governance mechanism is established by ZEC holders. The Lockbox amount is visible in block reward breakdowns.

Mining is the process of using computational power to solve cryptographic puzzles and add new blocks to the Zcash blockchain. Miners compete to find valid block solutions; the first to succeed earns the block reward (subsidy + transaction fees). Mining secures the network and processes transactions.

Zcash uses the Equihash proof-of-work algorithm, which is memory-intensive by design. This originally aimed to make it more resistant to specialized ASIC mining hardware, though Equihash ASICs have since been developed.

The network solrate is an estimate of the total computational power securing the Zcash network. Because Zcash uses the Equihash algorithm, it's measured in Solutions per second (Sol/s) rather than "hashes per second." You'll see this abbreviated as KSol/s, MSol/s, GSol/s, or TSol/s on the explorer. The terms "solrate" and "hashrate" are used interchangeably in the mining community, but solrate is the technically correct term for Zcash.

It can't be measured directly. Instead, it's inferred from block difficulty using the formula difficulty × 8192 / 75. Higher solrate means more mining power is protecting the network. For a full explanation of how this works, see the How Solrate Is Estimated guide.

There's no way to directly count every miner on the network. Miners connect and disconnect freely without registering anywhere. Instead, we infer solrate from difficulty, a value the network adjusts to keep blocks arriving at the target 75-second pace.

This means the solrate you see is a statistical inference, not a direct measurement. It's very accurate over longer time periods, but can fluctuate in the short term because individual block times naturally vary. The learn guide covers the math in detail.

This explorer estimates a pool's solrate from the blocks it has mined: specifically, the pool's share of recent blocks multiplied by the estimated network solrate. A pool's own dashboard measures solrate from the shares submitted by its miners, which is a more direct (but private) measurement.

Over short periods, luck causes variance: a pool might find more or fewer blocks than expected. A pool with 30% of the network solrate won't always mine exactly 30% of blocks in every window. Over longer periods (days to weeks), the two numbers converge. For more detail, see the per-pool solrate section of the learn guide.

Difficulty is a measure of how hard it is to find a valid block hash. The Zcash network automatically adjusts difficulty to maintain the target 75-second block time. If miners are finding blocks too quickly, difficulty increases; if too slowly, it decreases. The Mining page shows a historical difficulty chart alongside solrate, and each block's individual difficulty is displayed on its detail page.

Mining pools are groups of miners who combine their computational resources to increase their chances of finding blocks. When the pool finds a block, the reward is shared among participants based on each miner's contributed work.

Solo mining has become extremely unlikely to produce blocks for individual miners due to the high network solrate. Pools make mining income more predictable. The Pools page shows which pools are mining Zcash blocks, their share of the network, and estimated solrate. Each pool has a detail page with historical stats, coinbase tags, and payout addresses.

Zcash targets a 75-second block time since the Blossom upgrade (December 2019, block 653,600). Before Blossom, the target was 150 seconds. This means a new block is expected roughly every 1 minute and 15 seconds, resulting in approximately 1,152 blocks per day. The "Avg Block Time" on the Dashboard shows the actual average computed from recent blocks, which will fluctuate around the 75-second target.

The coinbase transaction is the first transaction in every block. It creates new ZEC out of thin air as the block reward. This is how new coins enter circulation. Unlike regular transactions, a coinbase transaction has no inputs (no previously existing coins being spent).

On block detail pages, you can see the coinbase transaction's details including the coinbase text (arbitrary data embedded by the miner, often containing the pool name or software version), the payout address, and the full breakdown of outputs including the miner reward, ZCG allocation, and lockbox funds.

The coinbase text (also called the "coinbase scriptsig" or "coinbase data") is a small field in the coinbase transaction where the miner can embed arbitrary data. Mining pools typically use this to include their pool name, a worker identifier, or the block height. On block detail pages, this explorer decodes the raw hex coinbase data and displays the human-readable text. This is also how the explorer identifies which pool mined a block by matching known coinbase tags.

The mempool (short for "memory pool") is a holding area for unconfirmed transactions waiting to be included in a block. When you send a ZEC transaction, it first enters the mempool. Miners select transactions from the mempool to include in the next block, typically prioritizing those with higher fees.

The Mining page displays live mempool statistics: the current number of pending transactions, total size in bytes, total pending fees, and average fee per transaction. The pending transactions table shows individual unconfirmed transactions sorted by fee. This data updates in real-time via WebSocket when available.

A network upgrade is a planned protocol change that adds new features, improves performance, or adjusts consensus rules. Zcash network upgrades are activated at specific block heights and require nodes to update their software. Unlike contentious hard forks, Zcash upgrades are coordinated by the community and development teams. Major upgrades include Sapling, Blossom, NU5, and NU6, each visible as milestones on the Dashboard emission curve chart.

Sapling (activated October 2018, block 419,200) was a major upgrade that introduced a new shielded pool with vastly improved performance. Before Sapling, creating a shielded transaction required significant memory and time (sometimes over a minute). Sapling reduced proof generation to just a few seconds with minimal memory, making shielded transactions practical for everyday use and mobile wallets. Sapling addresses start with "zs".

Blossom (activated December 2019, block 653,600) halved the target block time from 150 seconds to 75 seconds. This doubled the transaction throughput of the network and reduced confirmation latency. To maintain the same emission schedule, the block reward was also halved at Blossom (from 12.5 ZEC to 6.25 ZEC per block), keeping the daily issuance rate constant. The halving interval was adjusted from 840,000 blocks to 1,680,000 blocks accordingly.

NU5 (activated May 2022, block 1,687,104) introduced the Orchard shielded pool, which uses the Halo 2 proving system. Halo 2 is notable because it eliminates the need for a trusted setup ceremony, a process that previous shielded pools (Sprout and Sapling) required to generate cryptographic parameters.

Orchard transactions are labeled with the "Orchard" badge on this explorer. The Orchard pool is tracked in the value pool distribution chart on the Dashboard.

NU6 was activated alongside the 2nd halving in November 2024 (block 2,726,400). Its most significant change was the introduction of the Lockbox (Coinholder-Controlled Fund). A portion of each block reward is now locked on-chain in the Lockbox, where it accumulates until a future governance mechanism, determined by ZEC holders, decides how to deploy the funds. NU6 also restructured the development fund allocations for the new halving era.

A block is a bundle of transactions that has been validated and permanently added to the blockchain by a miner. Each block contains a header (with metadata like the timestamp, difficulty, and reference to the previous block) and a list of transactions. Blocks are chained together in sequence, where each one references the hash of the previous block, forming the immutable blockchain ledger.

Block height is the sequential number of a block in the blockchain, starting from 0 (the genesis block). Height increases by 1 with each new block. You can search for any block by its height using the explorer search bar. The current block height is displayed prominently on the Dashboard and represents the total number of blocks that have been mined.

A block hash is a unique 64-character hexadecimal identifier produced by hashing the block's header data. It serves as a cryptographic fingerprint; if even one bit of the block data changed, the hash would be completely different. You can look up any block by its hash in the explorer search bar. On the block detail page, the full hash is displayed below the block height.

A transaction ID (txid) is a unique 64-character hexadecimal hash that identifies a specific transaction. It's computed from the transaction's data and serves as its permanent, unique fingerprint on the blockchain. You can search for any transaction by its txid in the explorer search bar.

Zcash uses a UTXO model where transactions consume inputs (previously received coins) and create new outputs (coins sent to recipients). It works like spending physical bills: you hand over existing bills (inputs) and receive change back (outputs).

On transaction detail pages, the explorer shows a two-column layout: inputs on the left (where the funds came from) and outputs on the right (where they went). For shielded transactions, inputs and outputs are encrypted, so you'll see "Shielded Input" or "Shielded Output" placeholders since the actual values are hidden.

UTXO stands for Unspent Transaction Output. When you receive ZEC, the transaction creates an output assigned to your address. That output remains "unspent" until you use it in a future transaction. Your wallet balance is the sum of all your UTXOs. On address detail pages, the explorer shows the UTXO count, which is the number of individual unspent outputs held by that address.

Each Zcash block reward is split among several recipients, visible in the reward breakdown bar on block detail pages:

• Miner Subsidy: The majority of the block reward, paid to the miner (or pool) that found the block.
• Transaction Fees: Fees paid by users for their transactions in the block. These go to the miner on top of the subsidy.
• Zcash Community Grants (ZCG): A portion of the block subsidy directed to community-driven development grants.
• Coinholder-Controlled Fund (CCF): A portion locked in an on-chain lockbox, held for future governance decisions by ZEC holders.

The exact percentages and amounts depend on the current halving era and the development fund rules active at that block height.

Each transaction on the explorer is labeled with a type badge indicating its privacy characteristics:

• Coinbase: The special first transaction in each block that creates new ZEC as the mining reward.
• Transparent: All inputs and outputs are public, publicly visible on the blockchain.
• Shielded: The transaction has both shielded inputs and shielded outputs (Sapling pool) where amounts and addresses are encrypted.
• Orchard: The transaction uses the Orchard shielded pool (NU5+) with Halo 2 proofs, the newest and most advanced privacy technology.
• Mixed: The transaction has a combination of transparent and shielded components, for example, shielding (moving from transparent to shielded) or deshielding (the reverse).