Ethereum Upgrade History¶
Ethereum executes upgrades through hard forks. The following lists Ethereum's major upgrades in chronological order.
PoW Era¶
Frontier (Genesis)¶
Date: July 30, 2015
Ethereum's first block, also known as Frontier, occurred nearly two years after its initial conception.
Homestead¶
Date: March 2016
Ethereum's first planned upgrade, marking the network's transition from a testing phase to a more stable stage.
The DAO Hack and Fork¶
Date: June - July 2016
A large venture capital fund (The DAO), crowdfunded by the Ethereum community, was hacked. A controversial hard fork was implemented to recover the lost funds.
Tangerine Whistle¶
Date: October 2016
An upgrade in response to denial-of-service attacks, adjusting Gas costs for certain operations.
Spurious Dragon¶
Date: November 2016
Continued response to denial-of-service attacks and cleaned up the blockchain state.
Byzantium¶
Date: October 2017
The first part of the Metropolis upgrade, introducing multiple improvements and optimizations.
Constantinople¶
Date: February 2019
The second part of the Metropolis upgrade, further optimizing EVM performance.
Istanbul¶
Date: December 2019
Enhanced Ethereum's resistance to denial-of-service attacks and improved interoperability with Zcash.
Muir Glacier¶
Date: January 2020
Delayed the difficulty bomb to allow more time for subsequent upgrades.
Beacon Chain (Launch)¶
Date: December 1, 2020 Layer: Consensus Layer
This marked the beginning of Ethereum's transition to a Proof of Stake consensus mechanism and served as the genesis of what is now the consensus layer. The Beacon Chain ran in parallel with the existing execution layer.
Berlin¶
Date: April 2021
Optimized Gas costs for certain operations in preparation for The Merge.
London¶
Date: August 2021
Introduced the EIP-1559 burn mechanism, changing how the transaction fee market operates. The base fee is burned, reducing the supply of ETH.
Altair¶
Date: October 27, 2021
The first upgrade to the Beacon Chain. Introduced sync committees, laying the groundwork for light client support. Ethereum clients began to be divided into two parts: the Execution Layer and the Consensus Layer. Altair was a consensus layer release.
Bellatrix¶
Date: September 6, 2022 Layer: Consensus Layer
A preparatory upgrade for the Beacon Chain, laying the foundation for The Merge.
PoS Era¶
The Merge¶
Date: September 15, 2022 Layer: Execution Layer + Consensus Layer
The transition from Proof of Work to Proof of Stake, triggered by reaching the terminal total difficulty. This is one of the most important upgrades in Ethereum's history: - Mining stopped; instead, staking 32 ETH to become a validator - Energy consumption reduced by approximately 99.95% - Annual new ETH issuance significantly reduced - Combined with the EIP-1559 burn mechanism, ETH may become deflationary
Shapella (Shanghai + Capella)¶
Date: April 12, 2023 Layer: Execution Layer + Consensus Layer
A combined upgrade of Shanghai (Execution Layer) and Capella (Consensus Layer).
Enabled withdrawal of validator stakes from the Beacon Chain, completing the full transition to PoS. Allows validators to withdraw their staked ETH assets.
Dencun (Cancun + Deneb)¶
Date: March 13, 2024 Layer: Execution Layer + Consensus Layer
A combined upgrade of Cancun (Execution Layer) and Deneb (Consensus Layer).
Key improvements: - Added transient storage (EIP-1153) - Introduced Blobs through EIP-4844 (Proto-Danksharding), significantly reducing Layer 2 data costs, lowering Rollup fees by 10-100x, and substantially expanding Layer 2 capabilities
Pectra (Prague + Electra)¶
Date: July 2025 Layer: Execution Layer + Consensus Layer
A combined upgrade of Prague (Execution Layer) and Electra (Consensus Layer).
Key improvements: - EIP-7702: Account abstraction, improving user experience by allowing EOA accounts to operate like smart contracts - EIP-7251: Increased validator staking cap, improving validator experience and efficiency - Further enhancements to Ethereum's usability and efficiency
Fusaka (Osaka + Fulu)¶
Date: December 2025 Layer: Execution Layer + Consensus Layer
A combined upgrade of Osaka (Execution Layer) and Fulu (Consensus Layer).
Key improvements: - PeerDAS: Peer Data Availability Sampling, further expanding data availability - Gas optimization: Increasing the block Gas limit to 60 million - New precompiled contracts: Supporting the secp256r1 curve, unlocking native device signing capabilities
Reference Sources¶
- https://ethereum.org/ethereum-forks/
- https://ethereum.org/en/history/
- https://ethereum.org/en/roadmap/
- https://learnblockchain.cn/article/22310