Base activates Denim upgrade, replacing Flashblocks with 200ms blocks

Base has activated its fourth network upgrade, Denim, on mainnet. The upgrade replaces Flashblocks with five canonical blocks per second, produced at 200-millisecond intervals.

A block is a batch of transactions recorded on the blockchain. The change makes Base’s blocks arrive at a steady, short interval; the available announcement does not specify other changes or provide performance figures beyond the new timing.

What changes with Base’s Denim upgrade?

Denim replaces Flashblocks with a schedule of five canonical blocks each second. “Canonical” refers to blocks that form part of the network’s accepted chain, rather than an earlier or provisional view of activity.

For people using Base, faster block production may mean transactions appear in the chain more frequently. It does not, by itself, establish how quickly a transaction is final, or guarantee that every app will feel faster; those outcomes depend on factors beyond the block interval.

How does Denim compare to other speed-focused upgrades?

Denim arrives alongside other recent network upgrades targeting faster block times. Zcash’s NU7, which activated on November 5, cuts block intervals from 75 seconds to 25 seconds. Solana’s Alpenglow upgrade, which went live in October, targets roughly 150-millisecond finality by replacing the network’s voting system. These networks serve different purposes, so the figures are not a direct performance comparison—but they show why users should distinguish block timing from the broader experience of sending and confirming a transaction.

What should Base users watch next?

The upgrade is already active, so the next practical test is how wallets and apps behave on the upgraded network. Users do not need to interpret a 200ms block interval as a promise that every payment or trade will be fully settled in that time. Base’s previous upgrade, Beryl, introduced the B20 token standard and cut withdrawal delays to five days; Denim focuses on block production speed rather than those withdrawal mechanics.