A Look at the Recent and Upcoming Ethereum (ETH) Upgrades


Main Takeaways

  • Ethereum undergoes regular upgrades to make improvements to the network's technical capabilities. These are mainly done with hard forks.

  • Ethereum's next update, Shanghai, will allow staking withdrawals. We should also see a significant upgrade to introduce sharding sometime in 2023 or 2024.

  • Previous Ethereum updates have changed the network's fee structure (London) and consensus mechanism (the Merge).

Ethereum has introduced many vital upgrades over its life. Learn about some of its most recent, critical hard forks and what to expect in the future.

Ethereum has a long and exciting history when it comes to upgrades. Since its birth, we've seen numerous changes that have improved its functionality. It's one of the aspects that makes the network popular with users and developers alike. If you're an ether (ETH) holder or just crypto-curious, there's much to gain from understanding the network's origins, current state, and where it's headed in the future.

What Are Ethereum Upgrades?

Ethereum upgrades implement technical changes to the Ethereum network. These could improve scalability, alter the gas fee model, or affect the network's technical capabilities. A due process takes place to make changes that involve the development and vetting of Ethereum Improvement Proposals (EIPs) by the community and development team.

Most Ethereum updates require hard forks

Major updates will hard fork the Ethereum blockchain. This means that the new code implemented in an update is incompatible with the old code. To participate in the new upgrade, users running nodes must update their software. Any nodes and validators running the previous software will not produce valid blocks under the latest update. A soft fork, alternatively, allows validators and nodes still running the old code to create and verify blocks, even after the update.

A hard fork is necessary for updates with large, significant changes as it ensures everyone on the network is running the new code. This allows the user base to effectively agree on new upgrades. Should an upgrade not be popular under the hard fork system, a majority would simply stick with the original, unchanged blockchain.

For instance, the update turning Ethereum into a Proof of Stake (PoS) network wouldn't work if some validators were allowed to continue with Proof of Work (PoW). Any validator still using the old PoW mechanism would stay on the old, outdated blockchain and split off. This has happened previously on Ethereum with the DAO hack. Most users moved to a hard fork that reversed the hack, but many disagreed with the change, stayed on the older version of the blockchain, and renamed it Ethereum Classic (ETC).

Ethereum Major Upgrades

The Beacon Chain

The Beacon Chain upgrade (December 1, 2020) was the first step in Ethereum's move to PoS. The chain was introduced as Ethereum's new coordinating blockchain for creating and validating new blocks while rewarding ETH to validators. Locked ETH staking also was introduced along with the Beacon Chain. After the chain's creation, the original Ethereum PoW would merge with the chain to become one.

Ethereum's Merge

The Ethereum Merge (September 6, 2022) saw the merging of Ethereum's original PoW blockchain into the new, sharded PoS Beacon Chain. All smart contracts and transactional data transitioned to the Beacon Chain, successfully completing the PoS move.


Sharding implementation (planned for 2023/24) will be a major upgrade to increase Ethereum's scalability. The exact plans are still in development as the team reacts to improvements in scalable technology. 

There are a few options available. The first is to use sharded blockchains like a computer's RAM. They will offer data storage to the mainchain via a rollup process, allowing it to increase its transactions per second (TPS). The second is to execute code and process transactions on the shards themselves. Each shard would have its own stored smart contracts and account balances which it then shares across the whole Ethereum network.

Other Ethereum Upgrades Worth Knowing

Ethereum London Hard Fork

Ethereum's London Hard Fork (August 5, 2021) implemented five EIPs in preparation for the network's move to PoS. Its largest change was the introduction of transactions and a deflationary mechanism. Each block moved to a fixed gas fee instead of its previous bidding system. The difficulty time bomb was also extended to December 2021 to coincide with the planned Merge upgrade.

Ethereum Arrow Glacier Upgrade

The Ethereum Arrow Glacier Upgrade (December 9, 2021) was a minor update to once again delay the difficulty time bomb. This time, the team attempted to specifically target June 2022 for the "ice age".

The Next Ethereum Upgrade: Shanghai

The Ethereum Shanghai upgrade is a long-awaited fork that will implement staking withdrawals on Ethereum. For an extended time, users who staked as part of Ethereum's validation mechanism could not remove their stake. EIP-4895 resolves this issue and unlocks the 32 ETH staked behind each validator node. While some stakers may have used a third-party, liquid staking solution for their staked ETH, many had been waiting since the Beacon Chain's launch in December 2020.

Moving Beyond Sharding

The journey toward PoS and sharding has been a long one. With some time to go, it's interesting to think about what will be on the horizon after. Scalability is such a vast topic, and it cannot really be "completed." There likely will be a lot of fine-tuning as developers and users decide on the models to implement. Rollups, zero-knowledge proofs, and layer two solutions are all possible ingredients, but who knows what the recipe will be? We'll have to wait for the next hard forks to see.

Further Reading