Overview

Celo was launched in 2020 as a mobile-first Layer 1 blockchain designed to advance global financial inclusion through smartphone-accessible crypto payments and phone number-based addressing. Built on proof-of-stake consensus with a commitment to carbon neutrality, Celo’s L1 featured fast, low-cost transactions and native stablecoins like cUSD that powered a vibrant DeFi ecosystem.

In 2024, Celo began migrating from its Layer 1 architecture to become an Ethereum Layer 2 network built on the OP-Stack. This migration aimed to achieve greater scalability and interoperability while preserving Celo’s core mission and complete transaction history. The migration was completed in March 2025 at block 31,056,500.

This section documents the historical Celo Layer 1 blockchain before its completed migration to Layer 2 and does not reflect Celo’s current L2 architecture.

Technical Changes

The table below summarizes the technical changes involved in transitioning from Celo’s Layer 1 to Layer 2:

Aspect	Layer 1	Layer 2
Architecture	Single service, providing execution, consensus, and data availability.	Multiple services built on the op-stack with separate execution, data availability, and settlement layers.
Bridging	Third-party bridges connecting to various chains.	Additional native bridge with Ethereum alongside existing third-party bridges.
CELO Token	Lived on the Celo L1.	Lives on Ethereum; CELO on L2 represents CELO bridged from Ethereum.
Blocks	5s long, 50M gas.	1s long, 30M gas.
Extra Fields	—	Withdrawals & withdrawalsRoot, blobGasUsed & excessBlobGas, parentBeaconBlockRoot.
Removed Fields	—	Randomness, epochSnarkData.
Validator Duties	Operated the consensus protocol.	Validators will temporarily operate community RPC nodes.
Validator Rewards	Distributed at epoch blocks.	Distributed periodically via smart contract execution.
Sequencing	Determined by the output of consensus, run by validators.	Initially handled by a centralized sequencer with plans for decentralized sequencing later.
Precompiles	—	All Celo precompiles removed except for the transfer precompile which supports token duality.
EIP1559	Governable implementation on-chain.	Upgraded implementation with modified parameters across networks.
Hardforks	—	Cel2 hardfork for transition to L2 alongside other op-stack hardforks.
Transactions	—	Deprecated transactions include Type 0 with feeCurrency field and Type 124.
Finality	One block finality, instantaneous once block is produced.	Finality depends on trust in sequencer, batcher, proposer, and eigenDA, or ultimately on Ethereum.

For more detailed technical changes, see Celo’s L2 Migration Documentation.