Base plans 200ms block times with Denim mainnet upgrade

Coinbase's layer-2 network is targeting November 2026 to move from two-second blocks to five canonical blocks every second Base, the layer-2 network incubated by Coinbase, is getting ready to produce a new block every 200 milliseconds on mainnet. That works out to five blocks per second, on a chain that currently produces one every two seconds. The change arrives through an upgrade called Denim, which is targeted for mainnet activation in November 2026. From two seconds to a fifth of one Base currently produces 43,200 blocks per day at its two-second pace. Under Denim, that figure jumps to 432,000 blocks daily. It is a tenfold increase in block output, achieved without adding a single extra hour to the day. Denim has already gone live on Base Sepolia, the network’s testnet, where it was activated on October 21, 2026. The mainnet date of November 2026 remains a target rather than a locked-in launch. These 200-millisecond blocks will be real, settled blocks on the chain. They are not promises about what a block will eventually contain. Goodbye, Flashblocks Since July 2025, Base has run Flashblocks, a mechanism that provided preconfirmations inside each two-second block window. Precon...