Abstract

We will be increasing the block time on the Arbitrum One network from 250ms to 2 seconds (an 8x slowdown), and on other Arbitrum chains from 100ms to 2 seconds (a 20x slowdown). The primary goal is to align user experience with real-world expectations, balance transaction pacing with decision-making, and introduce a more deliberate tempo to onchain interactions. Contrary to conventional wisdom, faster isn’t always better—sometimes, slowing down is the true innovation.

Motivation

For too long, Arbitrum has been operating on hyper-speed, delivering near-instantaneous finality and blazing-fast blocks. While impressive, this speed may actually be alienating users accustomed to slower confirmation times across traditional chains. Our competitors have embraced these slower speeds, creating a sense of rhythm and pacing that users recognize and trust.

We believe it’s time to meet them where they’re at.

By extending block times to 2 seconds, we bring Arbitrum into a friendlier tempo for humans—not just machines—making blockchain feel less like a race and more like a conversation.

Rationale

Slower block times can yield a number of meaningful benefits:

• User Comprehension: 2 seconds is just fast enough to keep users engaged, but slow enough to give them a moment of reflection before submitting or interpreting transactions.
• UX Parity: Aligning with the rhythm of other chains (many of which have block times around 2s or more) reduces the cognitive gap for users switching to or from Arbitrum.
• Deliberate Decision-Making: Faster blocks often encourage rapid, sometimes impulsive, user behavior. Slower blocks provide space to double-check, consider, and confirm actions.
• Geographic Equity: Arbitrum is a global protocol, but not everyone needs (or benefits from) sub-300ms block production. A slower global cadence supports broader accessibility without sacrificing decentralization.
• Narrative Control: Moving fast has been done. Moving wisely is the new frontier. This gives Arbitrum the opportunity to redefine speed as a feature—not a default.

Key Terms

• Block Time: The time interval between consecutive blocks being produced on a blockchain network.
• Arbitrum One: The land of liquidity, currently operating at ~250ms block times.
• Arbitrum Chains: Other chains in the Arbitrum ecosystem, some of which currently operating at ~100ms block times.
• UX (User Experience): The overall experience a user has interacting with a protocol or product.
• Finality: The assurance that a transaction is permanent and cannot be reversed.

Specifications

• New Target Block Time (Arbitrum One): Increase from 250ms → 2s.
• New Target Block Time (Other Arbitrum Chains): Increase from 100ms → 2s.
• Implementation Mode: Staggered rollout across chains, with Arbitrum One updated first, followed by Nova and others.
• Configurability: Include optional settings to revert to even slower block times during congestion or emergencies.

Steps to Implement

1. Research & Modeling
   • We evaluated network throughput and UX performance under various pacing models.
   • Behavioral modeling helped determine the ideal tempo for interaction and comprehension.
2. Community Input
   • Developers, validators, and users provided input during open forums and working groups.
   • Feedback was overwhelmingly supportive of a slower, more predictable cadence.
3. Testnet Phase
   • Slower block times were deployed to test environments.
   • Performance was monitored across dApps, wallets, and infrastructure providers.
4. Mainnet Rollout
   • Arbitrum One was updated first, followed by Nova and other Arbitrum chains.
   • Builders on other Arbitrum chains were offered migration paths and configuration options.
5. Monitoring & Tuning
   • We continue to observe network metrics, gas efficiency, and user behavior post-rollout.
   • Additional tuning may occur as ecosystem needs evolve.

Conclusion

Speed was the revolution. Deliberation is the evolution.

By slowing down block times across the Arbitrum ecosystem, we’re making blockchain interactions more intentional, accessible, and human. This shift invites users to pause, reflect, and engage more thoughtfully—with the assurance that the network is still performant, scalable, and secure.

Arbitrum doesn’t just move fast. It moves with purpose.

Thank you to ChatGPT for helping us scope out this game-changing implementation.

Happy April Fools day!