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Network upgrades

PUBLIC PREVIEW DOCUMENT

This document is currently in public preview and may change significantly as feedback is captured from readers like you. Click the Request an update button at the top of this document or join the Arbitrum Discord to share your feedback.

This page has information on the state and timelines of major software updates to Arbitrum One and Arbitrum Nova. Software updates that alter an Arbitrum chain's ability to produce valid Arbitrum blocks are referred to as ArbOS upgrades and, as outlined in the Arbitrum DAO Constitution, will always require a Constiutional AIP to pass for DAO-governed chains.

Visit Inside Arbitrum Nitro to learn more about Nitro's architecture; more information about ArbOS software releases is available on the Arbitrum DAO forum as well as in the documentation for the overview of ArbOS software releases.

Network activation statuses​

UpgradeGovernance Approval StatusLink to most recent governance stageArbitrum Sepolia (YYYY-MM-DD)Arbitrum One (YYYY-MM-DD)Arbitrum Nova (YYYY-MM-DD)
ArbOS 32 BiancaApproved & executed by the Arbitrum Security CouncilN/AWeds, 2024-09-25 at 02:06:01 UTCWeds, 2024-09-25 at 02:37:30 UTCWeds, 2024-09-25 at 02:26:11 UTC
ArbOS 31 BiancaApproved & executedOn-chain Tally voteMon, 2024-06-17 at 17:00:00 UTCTues, 2024-09-03 at 17:00:00 UTCTues, 2024-09-03 at 17:00:00 UTC
ArbOS 20 AtlasApproved & executedOn-chain Tally voteThu, 2024-02-29 at 18:00:00 UTCThu, 2024-03-14 01:48:09 PM UTCThu, 2024-03-14 01:48:09 PM UTC
ArbOS 11Approved & executedOn-chain Tally voteTues, 2024-01-30 at 17:00:00 UTCThu, 2024-02-24 at 20:01:13 UTCThu, 2024-02-24 at 20:01:13 UTC

Stay up to date​

To stay up to date with proposals, timelines, and statuses of network upgrades to Arbitrum One and Nova: