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Network upgrade overview

This page provides hardfork activation timestamps and links to detailed specifications. The documentation outlines the hardfork release process. The network upgrade naming scheme after the Bedrock upgrade follows a geology theme based on the next letter in the English alphabet.

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Activations

Network upgrades are activated by timestamps. Failing to upgrade your OP Stack software before the timestamp will cause a chain divergence and you will need to resync the chain. Optimistic activation times refer to times that are pending governance approval.
UpgradeGovernance ApprovalMainnet ActivationsSepolia Activations
IsthmusapprovedFri May 9 16:00:01 UTC 2025 (1746806401)Thu Apr 17 16:00:00 UTC 2025 (1744905600)
HoloceneapprovedThu Jan 9 18:00:01 UTC 2025 (1736445601)Tue Nov 26 15:00:00 UTC 2024 (1732633200)
GraniteapprovedWed Sep 11 16:00:01 UTC 2024 (1726070401) around block 125235812Mon Aug 12 16:00:00 UTC 2024 (1723478400) around block 15837930
FjordapprovedWed Jul 10 16:00:01 UTC 2024 (1720627201) around block 122514212Wed May 29 16:00:00 UTC 2024 (1716998400) around block 12597930
EcotoneapprovedThu Mar 14 00:00:01 UTC 2024 (1710374401) around block 117387812Wed Feb 21 17:00:00 UTC 2024 (1708534800) around block 8366130
DeltaapprovedThu Feb 22 00:00:00 UTC 2024 (1708560000) around block 116480612Fri Dec 22 00:00:00 UTC 2023 (1703203200) around block 5700330
CanyonapprovedThu Jan 11 17:00:01 UTC 2024 (1704992401) around block 114696812Tue Nov 14 17:00:00 UTC 2023 (1699981200) around block 4089330
BedrockapprovedTue Jun 06 2023 16:28:23 UTC (1686079703) at block 105235063N/A

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Upgrade process

Network upgrades follow this general process in which the features included in the upgrade are put into a release version cut from the develop branch and then the software is deployed on production networks.
“Baking” on a network means the node software has been deployed and is live. Engineers take this time to observe the behavior of the software on production networks.
1

Devnet

  • Devnet Upgrade Notice Period is for core developers to upgrade the node software on an internal devnet prior to the activation timestamp.
  • Upgrade Activates on Devnet
  • Baking on Devnet
2

Testnet

  • Testnet Upgrade Notice Period is to allow testnet node operators to upgrade the node software on testnet prior to the activation timestamp.
  • Upgrade Activates on Testnet
  • Baking on Testnet
3

Mainnet

  • Governance Voting Review Period is when the Optimism Collective’s governance system reviews proposals, including network upgrade proposals.
  • Governance Voting Period is when the Optimism Collective’s governance system votes on proposals.
  • Veto Period is when the Citizens’ House of the governance system can veto a protocol upgrade that has been approved by the Token House.
  • Cut Mainnet Release
  • Mainnet Upgrade Notice Period is to allow mainnet node operators to upgrade the node software on mainnet prior to the activation timestamp.
  • Upgrade Activated

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More information

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