Base, Coinbase’s Layer 2 network, has slashed block times to just 200 milliseconds on its Sepolia testnet, marking a tenfold speed boost for Ethereum scaling. This tenfold increase in speed is designed to enhance transaction processing, providing faster confirmations and improved scalability for developers and users.
Flashblocks work by streaming preconfirmation blocks every 200 milliseconds, allowing transactions to be processed faster with early confirmations and built-in protection against reverts. This upgrade aims to improve the responsiveness and usability of the Base ecosystem, making it more efficient for decentralized applications (dApps) and high-frequency trading.
The technology was developed in collaboration with Flashbots, a well-known research and development group focused on Ethereum’s transaction ordering and MEV (Maximal Extractable Value) solutions. Flashblocks are expected to move to the Base mainnet in Q2 2025, following a successful test phase.
This approach is similar to what Uniswap recently implemented on its Unichain Layer 2 network, where Flashblocks have enabled 0.25-second block times. As Layer 2 solutions continue to evolve, faster and more scalable infrastructure could drive broader adoption of blockchain-based applications.
“Flashblocks make Base faster. This 10x change makes Base the fastest EVM chain to date, bringing effective block times from 2 seconds down to 200 milliseconds —and they’re live on testnet right now + coming to mainnet in Q2,” The Base Team said on X
Base Unveils Upgrades at ETHDenver 2025
Alongside its Flashblocks upgrade, Coinbase’s Layer 2 network Base has announced two additional innovations, Base Appchains and Smart Wallet Sub Accounts, designed to improve blockchain scalability and user experience. The announcement was made at ETHDenver 2025, with the protocol cementing its position as the most widely used Ethereum Layer 2 network by daily active users.
Base Appchains
Base Appchains introduce customizable, application-specific blockchains built on top of the OP Stack, allowing developers to create Layer 3 rollups within Base’s Layer 2 ecosystem. These dedicated blockchains provide custom gas tokens, optimized fee structures, and exclusive block space, making them ideal for high-traffic applications that require scalability and cost-efficiency.
By offering developers the flexibility to build custom Layer 3 solutions, Base aims to position itself as the go-to infrastructure for projects that demand tailored blockchain environments while still benefiting from Ethereum’s security.
Smart Wallet Sub Accounts
The team also introduced Smart Wallet Sub Accounts, a feature that enables users to manage multiple on-chain wallets from a single interface. This functionality is designed to simplify asset management, allowing for easier interaction with DeFi applications, NFT platforms, and blockchain games without requiring multiple wallet setups.
Scaling Ethereum with Base’s Optimistic Rollup
The base operates as an optimistic rollup, meaning it processes transactions off-chain and periodically posts data to the Ethereum mainnet. This approach reduces transaction costs and congestion while maintaining Ethereum’s security and decentralization. With Flashblocks, Appchains, and Smart Wallet Sub Accounts, Base is strengthening its position as a leading Layer 2 solution, offering both speed and scalability for the next wave of blockchain applications.
Following the successful testnet implementation, Base plans to deploy the Flashblocks upgrade on its mainnet in the second quarter of this year. This rollout is anticipated to bring the enhanced capabilities to a broader user base, facilitating faster and more efficient transactions across the network.
Quick Facts:
- Base’s Flashblocks upgrade reduces block times to 0.2 seconds on the testnet.
- Mainnet integration of Flashblocks is scheduled for Q2 of this year.
- The upgrade aims to improve transaction efficiency, bolstering Base’s position among Layer 2 solutions.
