Solana reduced its target slot time from 300 milliseconds to 250 milliseconds when mainnet crossed into epoch 1037 at 05:06 UTC on September 18. The change means the network aims to produce four slots per second, making blocks arrive nearly 17% faster.

This was the third reduction under SIMD-0525, a proposal that steps slot times down from the original 400 milliseconds in stages. The first cut went live at epoch 1020 in August and a second followed about a week later. Each leader's consecutive block window also shrinks, from 1.2 seconds to 1 second.

Shorter slots let wallets and applications receive network updates more often. They do not by themselves raise overall capacity, and they leave validators less time to receive and process each block, one reason the reductions have been introduced in stages.

One step remains, to 200 milliseconds, and no activation date has been announced. The change runs alongside separate work on Alpenglow, which targets finality rather than block frequency. Network stability at the new cadence will decide how quickly the final reduction follows.