Base, the Coinbase-incubated Ethereum layer 2 network, has activated its fourth major upgrade, Denim, on the mainnet after testing the release on Sepolia last month. The upgrade reduces block times tenfold to 200 milliseconds from two seconds, bringing the blockchain closer to transaction speeds expected in trading and payment applications, the team said Thursday.
Faster canonical blocks replace Flashblocks
Denim replaces Flashblocks with five complete canonical blocks per second. Transactions included in a block are now confirmed on the chain rather than appearing first in a provisional state that could later change.
Previously, Base produced one canonical block every two seconds and used Flashblocks to stream previews of pending transactions between blocks. Those previews could be dropped from the final block, forcing applications to account for changes between preconfirmed and canonical states.
With Denim, every 200ms block becomes part of the canonical chain. Standard RPC methods now expose the faster state, so developers no longer need separate Flashblocks subscriptions or reconciliation systems.
Millisecond timing and B20 changes
The upgrade also adds millisecond-level timing through BaseTime, enabling smart contracts to measure elapsed time more precisely for trading, auctions, order expirations, and DeFi functions. The network’s faster block cadence gives lending protocols, decentralized exchanges, and other applications more frequent opportunities to respond to market updates, including liquidations and rebalancing.
Denim includes three changes to B20 tokens, Base’s token standard. Issuers can now invert compliance policies through a NOT operator, reusing the same address list for allow and block rules, according to Base.
Transfer-executor policies now apply to all transfer methods, including direct transfers initiated by token holders, making it harder to bypass issuer-defined restrictions.
The upgrade also blocks transfers, mints, and seizures that send tokens to the token contract’s own address, preventing accidental transfers that could lock funds, the project added.
