Glamsterdam: The New Ethereum Upgrade

Ethereum activated the Glamsterdam upgrade on the Sepolia testnet on 6 October 2026.

It is the network's next major hard fork, changing how blocks are built, verified and priced. Glamsterdam has not yet been activated on the main network (mainnet), and no date has been officially confirmed.

Below, we explain what Glamsterdam brings, why it matters for Ethereum's scalability, and whether ETH holders need to do anything.

What is Glamsterdam and where does the name come from

Glamsterdam is Ethereum's next major upgrade after Fusaka, which went live on mainnet in December 2025.

The name combines two upgrades that activate at the same time: Amsterdam, the execution layer upgrade, named after a past Devcon conference location, and Gloas, the consensus layer upgrade, named after a star.

It is a hard fork, meaning a change to the protocol rules that all nodes must adopt at the same moment. A node that does not update its software stops following the main Ethereum chain.

Unlike some earlier upgrades, Glamsterdam brings no visible changes for end users. Its focus is structural scaling of layer 1: how blocks are built, propagated and processed.

Key changes in Glamsterdam

Glamsterdam consists of a set of Ethereum Improvement Proposals (EIPs), 15 of which relate to the execution layer. Three changes are the most important for understanding the upgrade.

Enshrined Proposer-Builder Separation (ePBS, EIP-7732)

On Ethereum today, a block is usually put together by a specialised builder, and the validator that proposes it to the network (the proposer) receives it through external intermediaries known as relays. This arrangement takes place outside the protocol itself.

ePBS brings this separation directly into the protocol rules. Builder commitments, the publication of block contents and payments to proposers become part of the consensus process. It also separates consensus validation from execution validation, giving validators more time to check block contents.

Block-Level Access Lists (BAL, EIP-7928)

Block-Level Access Lists record in advance which accounts and data the transactions in a block will access. When a node knows what each transaction touches, it can process multiple transactions in parallel rather than one at a time. The same change should also speed up the synchronisation of new nodes with the network.

Larger block capacity and new gas rules

Gas is the unit used to measure computational work on Ethereum, and the gas limit determines how much of that work fits into a single block.

The Ethereum Foundation has set a target of 200 million gas per block after Glamsterdam. On Sepolia, validators can opt for blocks of up to 200 million gas, more than three times the previous 60 million on that network. This is a test target, not a final value.

The final gas limit for mainnet will only be decided after testing. Alongside this, several EIPs reprice operations in gas to better reflect the actual load they place on the network, particularly when creating and reading state data. The aim is to prevent state from growing too quickly as blocks get larger.

Larger block capacity may mean lower fees during periods of high demand, but the actual effect on fees will depend on the gas limit applied on mainnet.

What Glamsterdam means for ETH holders

ETH holders do not need to do anything. The upgrade is carried out by node operators and validators, who must update their software for both the execution and consensus layers. Your ETH stays at the same address and remains unchanged.

The Sepolia test does not affect mainnet. Tokens on testnets have no real value and are used solely by developers to test changes.

Precisely because the upgrade requires no action from users, be cautious of messages claiming otherwise. Major upgrades often attract scammers, so if anyone asks you to "upgrade", "migrate" or "swap" your ETH because of Glamsterdam, it is a scam. Never share your seed phrase, and never send crypto assets to addresses someone offers you under the pretext of an upgrade.

It is not possible to predict what effect Glamsterdam will have on the price of ETH. Technical improvements do not guarantee a change in price, which depends on a range of market factors.

When is Glamsterdam coming to mainnet

The exact mainnet activation date has not yet been announced. Ethereum.org currently lists the fourth quarter of 2026, noting that the date is unconfirmed. Some media reports mention October, but there has been no official confirmation so far.

The road to mainnet looks like this:

1. The original target was June 2026, but the launch was postponed to give development teams more time for testing.
2. In August 2026, the temporary public testnet Platåberget was launched for early testing of Glamsterdam.
3. In October 2026, Glamsterdam was activated on the Sepolia testnet.
4. If the Sepolia test goes as planned, the next step is the Hoodi testnet. Its date has not yet been set.
5. Developers will announce the mainnet date only after successful testing.

Alongside testing, the Ethereum Foundation has extended its bug bounty programme to Glamsterdam's specifications and EIPs. After Glamsterdam, the next upgrade in line is Hegotá, planned for 2027.

Glamsterdam is one of Ethereum's most extensive upgrades since the switch to proof-of-stake. Enshrined PBS, parallel transaction processing and larger block capacity should enable layer 1 to process more transactions without compromising security or decentralisation. The Sepolia test is just one step on the road to mainnet.

Disclaimer: Bitcoin Store is not a financial advisory firm and is not authorised to provide investment or financial advice. The opinions, analyses and other content on our website are for informational purposes only and should not be considered a basis for making investment decisions. Cryptocurrency trading involves speculation, and prices can fluctuate rapidly, which may result in the loss of your investment. Before investing in cryptocurrencies, be sure to seek independent advice and thoroughly understand the risks associated with this type of financial instrument.