Mainnet: Base Cobalt Upgrade - September 30th

Scheduled for Sep 30, 18:00 - 20:00 UTC

Scheduled

On Wednesday, September 30th at 18:00 UTC (Unix timestamp 1790791200), Base Mainnet will undergo the Cobalt upgrade.

Operators of Base Mainnet nodes must upgrade to the 1.4.2, or greater, release of the https://github.com/base/base software (https://github.com/base/base/releases/tag/v1.4.2).

Please note: https://github.com/base/base now hosts the public Base node previously published from base/node. More information can be found here: https://github.com/base/base#run-a-node

For more information on the Cobalt upgrade, please visit our docs: https://docs.base.org/upgrades/cobalt/overview.

Posted Sep 23, 2026 - 23:00 UTC

This scheduled maintenance affects: Mainnet (Client Software).