BNB Chain launches EVM-compatible Layer 2 network opBNB on testnet

BNB Chain, a blockchain ecosystem powered by Binance's BNB token, has launched a Layer 2 network called opBNB on testnet.

opBNB is an Ethereum Virtual Machine (EVM)-compatible scaling network that's based on Optimism's OP Stack and uses optimistic rollups, BNB Chain said Monday. Its purpose is to help increase transaction speed and reduce fees.

The current speed of its Layer 1 network BNB Smart Chain is about 2,000 transactions per speed, and the average cost per transaction is around $0.109, Arnaud Bauer, senior solution architect at BNB Chain, told The Block in an exclusive interview. opBNB, however, will support over 4,000 transactions per second and cost less than $0.005 per transaction on average, Bauer said.

BNB Smart Chain is part of the BNB Chain ecosystem, along with BNB Beacon Chain (the staking and governance layer of the BNB Chain ecosystem), BNB Greenfield (a decentralized data storage system) and zkBNB (a Layer 2 network based on zero knowledge or zk rollup technique). zkBNB is also currently in testnet form, having launched last September.

The mainnet of opBNB is expected to launch in the third quarter of this year.

EVM-compatible opBNB

When asked why BNB Chain was launching another Layer 2 network, Bauer said zkBNB is not EVM-compatible, but opBNB is, which will help the ecosystem grow further. EVM compatibility refers to the ability of a blockchain to support and interact with applications developed for blockchains that are compatible with the Ethereum computing environment.

The EVM compatibility is significant because it allows developers to easily port their existing Ethereum-based applications to other compatible platforms, enhancing interoperability and expanding the reach of decentralized applications, Bauer said.

With both zkBNB and opBNB now in place, Bauer sees BNB Chain directly competing with the Ethereum Layer 2 ecosystem that includes projects such as Arbitrum and Optimism. Even though opBNB is based on Optimism itself, Bauer said it offers a higher gas limit or block space of up to 100 million versus 30 million for Optimism. A higher gas limit indicates a larger capacity for computational work within a block, allowing for increased scalability and the processing of more transactions on the blockchain.

BNB Chain vs. Ethereum 

The BNB Chain ecosystem is still tiny compared to the Ethereum ecosystem. The total value locked or TVL in Ethereum-based applications is over $24 billion, and the TVL of BNB Chain-based projects is over $3 billion, according to DefiLlama data. Bauer said BNB Chain is "trying to push heavily on the innovation part" to bring more user-friendly applications into the ecosystem and grow its TVL.

The BNB token was recently deemed a security by the United States Securities and Exchange Commission (SEC) when it sued Binance, Binance.US, and their owner Changpeng Zhao on June 5. Bauer declined to comment on the lawsuit's implications on the BNB Chain ecosystem, saying the project is focused on continuing building.