What is zkSync?

ZKsync is a family of Ethereum layer 2 networks that use zero-knowledge proofs to process transactions cheaply while settling on Ethereum. Its flagship chain, ZKsync Era, is a zk-rollup built with a toolkit called the ZK Stack. The project is developed by Matter Labs, whose founder and CEO is Alex Gluchowski.

How does ZKsync Era work?

ZKsync Era executes transactions off Ethereum, groups them into batches, and sends Ethereum a validity proof showing the batch was computed correctly. Ethereum's contract accepts the new state only when the proof checks out. This is the zk-rollup model, and it relies on zero-knowledge proofs rather than a challenge window.

Era runs its own virtual machine, EraVM, which ZKsync describes as EVM-compatible. Most Solidity and Vyper contracts can deploy with little or no change, and common developer tools work with it. Era also has native account abstraction, which means wallets can be smart contracts that do things like let users pay fees in ERC-20 tokens or have an app sponsor gas.

ZKsync's docs say Era was the first member of the Elastic Network, a group of more than 15 connected ZK chains that share proofs and trustless bridging. Newer chains use ZKsync OS, a newer system paired with a RISC-V based prover called Airbender.

What is the ZK token?

ZK is ZKsync's governance token. It was first deployed on ZKsync Era, and on-chain governance for the network takes place there. According to The Block, the total supply is 21 billion ZK. In June 2024, 17.5 percent of that supply was set aside for an airdrop to 695,232 eligible wallets, with claims open until January 3, 2025. Matter Labs' team was allocated 16.1 percent and investors 17.2 percent, with their tokens locked for a year and then unlocking from June 2025 to June 2028. For background on how these drops work, see what is a crypto airdrop.

What is the difference between zkSync and Arbitrum?

Both are rollups that settle on Ethereum, but they check correctness in different ways. Arbitrum is an optimistic rollup, so batches are assumed valid unless someone proves fraud during a challenge period, and standard withdrawals to Ethereum wait for that window to close. ZKsync is a zk-rollup, so each batch comes with a validity proof. ethereum.org notes that zk-rollup exits have no built-in delay once the proof is verified, though generating proofs requires heavy computation.

They also differ in execution. Arbitrum's Nitro software is built on a fork of Geth, an Ethereum client, while Era uses its own EraVM, which is compatible with Ethereum tools but not identical.

What has changed at ZKsync recently?

CoinDesk reported that Matter Labs cut 16 percent of its staff in September 2024, and that the older ZKsync Lite network was scheduled to shut down in early 2026 as a planned sunset. In June 2025 Matter Labs unveiled the Airbender prover. Details like these change often, so check ZKsync's own docs for the current state of the network as of October 2026.