The Merge was the Ethereum upgrade that replaced proof-of-work mining with proof-of-stake consensus. It went live on 15 September 2022 at 06:42:42 UTC. It cut the network's energy use by about 99.95% and ended ETH mining. It did not lower gas fees, did not noticeably speed up transactions and did not create a new token. ETH holders did not have to do anything.
Most of the facts below come from the Ethereum Foundation's own pages (ethereum.org and blog.ethereum.org). They are the authoritative record for protocol dates, but they are a single institutional source.
What The Merge actually did
Before September 2022, Ethereum ran on two chains side by side:
- The original Mainnet, secured by proof of work. Miners competed with computing power to produce blocks.
- The Beacon Chain, a separate proof-of-stake chain launched on 1 December 2020 at 12:00:23 UTC. It started once 16,384 deposits of 32 ETH had been made. For almost two years it reached consensus among validators but carried no user transactions.
The Merge joined them. Mainnet's transaction history and state became the execution layer, and the Beacon Chain became its consensus layer. In ethereum.org's words, the upgrade's main feature was "switching off the proof-of-work mining algorithm and associated consensus logic." Blocks are now proposed and attested by validators who lock up ETH as collateral, not by miners spending electricity.
How the switch was triggered
The switch was triggered by a terminal total difficulty (TTD), not by a calendar date. Developers chose a cumulative proof-of-work difficulty of 58750000000000000000000. The last proof-of-work block was the one that crossed it, block 15,537,393, and proof of stake took over from block 15,537,394. The trigger depended on miners' hash rate, so the Ethereum Foundation's 24 August 2022 announcement could give only an expected window of 10 to 20 September 2022.
The Merge had two parts:
| Upgrade | Layer | Date (UTC) | Role |
|---|---|---|---|
| Bellatrix | Consensus (Beacon Chain) | 6 Sep 2022, 11:34:47, epoch 144,896 | Prepared the Beacon Chain for the Merge |
| Paris | Execution | 15 Sep 2022, 06:42:42 | Ended proof of work once TTD was reached |
Before mainnet, the transition was rehearsed on public testnets. The Foundation's announcement confirms that the Goerli testnet had merged with its Prater beacon chain.
What changed and what didn't
Changed
- Energy use. ethereum.org puts the drop in energy consumption at about 99.95%.
- Mining ended. You can no longer mine ETH. Block production now depends on staked ETH.
- Issuance fell. Before the Merge, miners received about 13,000 ETH a day and stakers about 1,700 ETH a day. Now only the roughly 1,700 ETH a day to stakers remains, which ethereum.org says cut total new issuance by about 88%. That is about 0.52% a year.
- Block timing and finality. Blocks now come in fixed 12-second slots. Under proof of work the target was about 13.3 seconds, so blocks arrive about 10% more often. The Merge also introduced transaction finality.
Did not change
- Gas fees. The Merge changed how consensus works, not how much the network can process. ethereum.org says it "was never meant to lower gas fees."
- Transaction speed for users. Apart from the shorter slot time, speed is mostly the same.
- Your ETH. No new coin was issued and no swap was needed. ethereum.org: "you do not need to do anything with your funds or wallet." Anyone who said otherwise during the transition was very likely running a scam.
- Staking withdrawals. These were not enabled by the Merge. They came with the Shapella upgrade on 12 April 2023.
Is ETH deflationary now?
Not automatically. Since the London upgrade in August 2021, the base fee on each transaction has been burned, and the Merge did not change that. According to ethereum.org, the burn cancels out the daily issuance of about 1,700 ETH only when the average gas price that day is at least 16 gwei. Whether supply shrinks or grows therefore depends on network demand.
From Beacon Chain to Glamsterdam
Step through the upgrades before and after The Merge to see what changed on each date.
- 1 Dec 2020Beacon Chain launchesdone
A separate proof-of-stake chain starts at 12:00:23 UTC, once 16,384 deposits of 32 ETH had been made. It reaches consensus among validators but carries no user transactions.
- 6 Sep 2022Bellatrixdone
The consensus-layer upgrade at 11:34:47 UTC, epoch 144,896, prepares the Beacon Chain for the Merge.
- 15 Sep 2022Paris: The Mergedone
At 06:42:42 UTC, block 15,537,393 crosses the terminal total difficulty and proof of stake takes over from block 15,537,394. Energy use falls by about 99.95% and new issuance by about 88%. Gas fees do not change.
- 12 Apr 2023Shapelladone
Staking withdrawals are enabled. The Merge had not enabled them.
- 13 Mar 2024Dencundone
EIP-4844 (proto-danksharding) adds blobs, which make data cheaper for layer 2 rollups.
- 7 May 2025Pectradone
EIP-7251 raises the maximum effective balance per validator from 32 to 2,048 ETH. EIP-7702 lets ordinary accounts act like smart-contract wallets.
- 3 Dec 2025Fusakadone
With PeerDAS, each full node holds about 1/8 of blob data, which allows a theoretical 8x increase in blobs. Pre-Merge history data expires, and the default gas limit becomes 60 million (EIP-7935).
- 22 Oct 2026Glamsterdam Hoodi activation postponedpostponed
Activation on the Hoodi testnet, set for 26 October 2026, is postponed so EIP-8037's interactions with mainnet smart contracts can be investigated further. No new date and no mainnet date have been set. Mainnet users and ETH holders do not need to do anything.
This timeline lists only the mainnet upgrades and the testnet delay described in the article. It does not show individual testnet merge dates or any unconfirmed future mainnet date, and it does not say what any upgrade means for ETH's price.
Who was affected
- ETH holders: No action needed.
- Miners: Their ETH mining hardware stopped earning ETH rewards.
- Node operators: A full node now needs two programs, an execution client and a consensus client, connected by a shared JWT secret.
- Stakers: Running a validator requires 32 ETH. Validators should also set a fee recipient address to receive tips and MEV. You do not need to stake to run a node: anyone can run a non-validating node.
What came after The Merge
The Merge did not raise capacity. Later upgrades were the ones that addressed scaling and usability:
| Upgrade | Mainnet date (UTC) | Main changes |
|---|---|---|
| Shapella | 12 Apr 2023 | Staking withdrawals |
| Dencun | 13 Mar 2024 | EIP-4844 ("proto-danksharding"): "blobs" make data cheaper for layer 2 rollups |
| Pectra | 7 May 2025 | EIP-7251 raises the maximum effective balance per validator from 32 to 2,048 ETH; EIP-7702 lets ordinary accounts act like smart-contract wallets |
| Fusaka | 3 Dec 2025 | PeerDAS: each full node holds about 1/8 of blob data, allowing a theoretical 8x increase in blobs; history expiry for pre-Merge data; default gas limit of 60 million (EIP-7935) |
Latest: Glamsterdam is on hold (October 2026)
The next upgrade, Glamsterdam, has no mainnet date. Its execution side is called Amsterdam and its consensus side Gloas. According to the Ethereum Foundation's 16 October 2026 announcement, its headline changes are:
- Enshrined proposer-builder separation (EIP-7732): separating the roles of block proposer and block builder within the protocol itself.
- Block-level access lists (EIP-7928).
- Gas repricing (EIP-8037 and EIP-8038): making it more expensive to create state.
Activation on the Hoodi testnet had been scheduled for 26 October 2026, with a gas limit increase to 200 million. On 22 October 2026 the Foundation postponed it. Core developers decided on All Core Devs Execution call #248 "to allow for further investigation of interactions of EIP-8037 with mainnet smart contracts." No new date has been set. The Foundation says no action is required from mainnet users or ETH holders.
Key takeaways
- The Merge (15 September 2022) changed Ethereum's consensus from proof of work to proof of stake. It did not change ETH itself.
- Energy use fell by about 99.95% and new issuance by about 88%. Fees and throughput did not change.
- Lower layer 2 costs came later, from Dencun and Fusaka, not from the Merge.
- As of 25 October 2026, Glamsterdam's testnet activation is postponed and its mainnet date is undecided.
Limitations: protocol figures and dates come mainly from Ethereum Foundation publications; issuance figures are ethereum.org's approximations.
