ZK Rollups 101: Understanding the Basics and Top Projects to Watch Out for in 2023

Top 5 ZK-Rollup projects to watch out for in 2023
What are the most popular ZK-rollup blockchains? The top ZK-rollup blockchains include StarkNet, zkSync, and Polygon Zero.

If you are into the blockchain, you must have heard of “the blockchain trilemma.” It is a famous term coined by Ethereum founder Vitalik Buterin. The Blockchain Trilemma refers to the challenges developers face in creating a scalable, decentralized, and secure blockchain without sacrificing any of these characteristics. The most widely used network Ethereum has struggled with scalability. Network congestion and high gas fee have prohibited the network’s mass adoption. However, there is a solution to the scaling problem for Ethereum: ZK-Rollups. This post will introduce you to them, their benefits, and the top projects that use this technology.

What are ZK-Rollup projects?

ZK Rollup stands for a zero-knowledge rollup. These smart contracts implement Ethereum Layer 2 scaling solutions for more efficient transaction processing on the blockchain.

Vitalik Buterin has spoken about the Rollup technology in his blog post Endgame”.

Rollups are among the most popular Layer 2 solutions because they provide a high throughput (transactions per second) without giving up security or decentralization. 

Why ZK-Rollup projects are the next big narrative?

ZK-Rollups use blockchain space more efficiently since they require less storage than traditional smart contracts. This is because they require “zero knowledge” of the transaction’s data. ZK Rollups need only validation proofs, making validation quicker and less expensive with minimal data.

  • Faster transactions: they provide speedier transaction finality time (the time it takes a user to get confirmation that a blockchain transaction will not be modified or canceled).
  • Increased throughput and scalability: Because each transaction contains minimum data, ZK-Rollups improve performance and scalability. It combines all transactions into a single one, subsequently validated.
  • Lower transaction costs: ZK-Rollups enable lower transaction fees. Because their transactions are packaged or “rolled up,” users split the gas expense among themselves.
  • Decentralized yet secure: Since ZK-Rollups are “zero-knowledge,” only the validity evidence is required to access data, rather than the whole transactional data. Because the validity evidence is held on Layer 1, the rollup can boost scalability while keeping the layer safe and decentralized.

Top 5 ZK-Rollup projects

Polygon Zero

While ZK-rollups can improve scalability, their utility is restricted by the time-consuming and expensive proof-generation procedure. Polygon Zero addresses this issue by employing recursive proofs quicker than previous prover systems.

Typically, ZK provers make proofs for one transaction at a time. However, Polygon’s (ZKRU) project, Polygon Zero, generates proofs for all transactions in a batch simultaneously before rolling those proofs into a single proof for the main chain.

Polygon Zero is not only the quickest proving technique, but it also consumes far fewer processing resources than other projects that rely on this technology.


zkSync is an Ethereum-based trustless protocol for scalable, low-cost payments. They aim to achieve a VISA-like scale of throughput of thousands of transactions per second.

With zkSync, you can effortlessly redeploy existing active smart contracts from Ethereum. In addition, zkSync is the only ZK-Rollup protocol that fully supports EVM compatibility. This appeals to developers that wish to use the same code across Layers 1 and 2.

Total Value Locked (USD): $73.46 M


StarkNet is a permissionless decentralized ZK-Rollupthat functions as a Layer 2 network atop Ethereum, allowing decentralized applications to grow. Starknet’s gas prices are 100x lower than main chain transactions, making it suitable for increasing the affordability of transaction-heavy dApps.

  • Total Value Locked (USD): $1B
  • Total Number of Transactions (All Deployments): 173M
  • Cumulative Trading (USD): $602B
  • NFT’s Minted: 56.2M
  • Source: StarkEx (May 25, 2022)


The Loopring network is a ZK-Rollup-powered initiative that allows developers to build exchanges or DEXs with quick settlement for Ethereum network traders. Loopring DEXs use the high-throughput advantage of ZK proofs to provide low-cost trade and payment on the Ethereum blockchain.

Immutable X

Immutable X is an Ethereum Layer 2 scaling solution for Non-Fungible Tokens (NFTs). It employs ZK-Rollups to scale up immediate trading and remove gas expenses for NFT minting and trading, all while maintaining user and asset security.

Immutable X is at the crossroads of three prominent crypto narratives: NFTs, Rollups, and Gaming. Zero gas fees for trading NFTs draw more and more developers to the platform. As a result, Immutable X may experience significant growth. 

Final Thoughts

Ethereum recently switched to a Proof-of-Stake consensus process known as– The Merge. However, the process had little effect on scalability or gas fees. The scalability changes may occur following the third phase’s conclusion, enhancing Ethereum’s transaction throughput.

So the question arises, will layer-2 solutions like Polygon, Arbitrum One, and Loopring be viable after the Merge? Industry experts believe the Merge won’t impact L2s, as the Merge won’t solve the scalability solutions immediately. Likewise, most L2 solutions, such as Polygon, have said that the change of consensus for Ethereum won’t reduce the need for such L2 scaling solutions. On the contrary, the Merge may make L2s more environmentally friendly. Polygon claimed it would eventually cut its carbon emissions by 60,000 metric tons, or 99.91% of its current Value.

Hence, it is safe to say that L2 solutions are here to stay and will be the go-to scaling solutions for developers.