Dear Celo & Ethereum Community,
As of block 31056500 on March 26, 2025, Celo is officially operating as an Ethereum Layer 2.
This marks a defining moment for the Celo network—and a major step forward in our long-standing alignment with Ethereum’s values, vision, and future.
By becoming a Layer 2 secured by Ethereum and built on the Optimism OP Stack, Celo now inherits the strength of Ethereum’s security, gains access to its robust tooling and developer ecosystem, and becomes part of the broader effort to scale Ethereum for the real-world.
Built on Ethereum, for Ethereum
This transition was a deliberate commitment to Ethereum’s future.
Celo has transformed from an independent EVM-compatible Layer 1 into a fully integrated Ethereum Layer 2—rebuilt on the Optimism OP Stack, secured by Ethereum, and powered by EigenDA for scalable, cost-efficient data availability.
It was a ground-up re-architecture that preserves what made Celo distinct—fast finality, usability, and a strong focus on real-world applications—while aligning deeply with Ethereum’s technical standards and long-term roadmap.
Key highlights of the upgrade:
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Ethereum Security – Celo transactions are now anchored to Ethereum, inheriting its battle-tested consensus and decentralization.
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1-Second Block Times – Transactions are faster and confirmations near-instant.
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No Regenesis Required – Full chain history has been preserved, eliminating friction for users, developers, and explorers.
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Massive Tech Debt Reduction – Over 365,000 lines of legacy code diff was removed between Celo’s original client and Ethereum’s geth.
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Trustless Upgrade Path – Node operators were able to migrate without needing to resync, using trustless data conversion tools.
Celo now stands as a fully-aligned Ethereum Layer 2—by architecture, by ecosystem, and by mission.
Why This Matters
This upgrade is about more than performance or scalability—it’s about alignment.
By becoming a true Ethereum L2, Celo now:
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Joins a shared roadmap focused on rollups and modular scalability
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Gains deeper composability with Ethereum-native apps and protocols
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Unlocks developer access to the full suite of Ethereum tools and libraries
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The CELO asset is now native on Ethereum, and bridged to the L2 chain. Expanding its presence and liquidity
The cLabs team has long believed Ethereum is the best foundation for web3. And we’re proud that Celo is now contributing directly to that future—not from the outside, but from within.
What’s Comes Next for Celo L2
Mainnet is live, but the work continues:
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Developer Support – We’re focused on helping builders deploy, optimize, and integrate with the new L2 architecture.
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Community Calls – Weekly calls continue to support developers, and partners as they onboard and scale.
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Path to Stage 1 – In the coming months, we’ll be shipping fraud-proof enhancements, refining exit mechanisms, and continuing our progress toward decentralization as a mature L2.
Built Together
This milestone is the result of deep collaboration and commitment from across the Celo community. From the engineers who rewrote the client, to the validators who upgraded testnets, to the builders and partners who stress-tested every stage—thank you.
You made this possible.
Celo is now a Layer 2. Secured by Ethereum. Built for the real world.
The cLabs Team