Solana activates 350-millisecond slots on mainnet, first block time reduction since launch

Aug 21, 2026

Solana has activated its first-ever slot-time reduction on mainnet, shortening target slots from 400 to 350 milliseconds via the Agave v4.2 client. This upgrade is the first of four planned 50-millisecond steps aimed at reaching a 200-millisecond block time. While the speed increase enhances transaction latency and censorship resistance, validators can pause the rollout if block skip rates climb, addressing ongoing concerns over network reliability.

Slot-time reduction to 350ms

▪The SIMD-0525 proposal establishing the shorter slot times was approved and merged on May 14, 2026, and is active on Mainnet Beta at slot 440,208,000 in epoch 1019
▪Solana activated a mainnet feature that reduced its target slot time from 400 milliseconds to 350 milliseconds, marking the network's first slot-time reduction since its inception

Staged rollout to 200ms

▪The Solana slot-time reduction to 350 milliseconds is the first of four planned 50-millisecond steps aimed at reaching a final target of 200 milliseconds
▪At the final 200-millisecond target, Solana's block production rate will double from approximately 144 blocks per minute to 300 blocks per minute
▪Each 50-millisecond reduction step will activate through a separate feature gate in a later epoch, allowing the network to pause if block skip rates climb

Validator client technical requirements

▪The live tracker at solana.com/200ms showed 96.7% of Solana's network stake was already running the required upgrade software
▪The slot-time reduction upgrade does not change the number of ticks per slot, the four-slot leader span, or the number of slots in an epoch
▪The slot-time reduction is carried by Anza's Agave v4.2 validator client, which requires individual feature gates to switch on each step separately

Bitcoin block-time comparison

▪While Solana produces blocks much faster than Bitcoin, Bitcoin requires approximately one hour to settle a transaction for good compared to Solana's 13 seconds
▪Solana's target block time of 200 milliseconds is significantly faster than Bitcoin's average block production time of one block every 10 minutes

Ethereum block-time comparison

▪While Solana produces blocks faster than Ethereum, Ethereum requires approximately 13 minutes to reach transaction finality compared to Solana's 13 seconds
▪Solana's target block time of 200 milliseconds is significantly faster than Bitcoin's average block production time of one block every 10 minutes

Network skip-rate reliability concerns

▪Solana validators can pause the staged slot-time reduction sequence at any point if block skip rates become too high
▪Solana experienced reliability issues in August 2026 when a routing fault knocked 28.83% of staked SOL offline, bringing the network close to a halt