Ethereum Glamsterdam upgrade: Sepolia test on October 6, new gas prices and what ETH holders should do

When and where Glamsterdam goes live

Glamsterdam is Ethereum's next hard fork. The name joins two halves. Amsterdam covers the execution layer, where transactions and smart contracts run. Gloas covers the consensus layer, where validators agree on blocks. Both layers upgrade at the same moment, so node operators have to install new versions of both clients.

According to the Ethereum Foundation announcement, the schedule looks like this:

Sepolia will be the first public network to run Glamsterdam. Until now the upgrade was tested on private developer networks. Hoodi is the second testnet: CoinCentral and Cointribune report that developers are aiming for October 27, but the final call will only come after Sepolia. The foundation promises a separate announcement for mainnet, and ethereum.org currently lists the upgrade for Q4 2026. If the tests turn up problems, the timeline will slip: a mainnet date won't be set until Hoodi is done. ETH holders don't need to plan around these dates: the hard fork doesn't touch balances, so you can buy ETH on a no-KYC crypto exchange or keep holding it without watching the schedule.

What changes

Glamsterdam includes 18 core Ethereum Improvement Proposals (EIPs). For an ordinary user, four topics matter: how blocks are built, how they are verified, what gas costs and how much work fits in a block.

Builders and proposers are separated in the protocol

Today a block on Ethereum is usually not built by the validator itself. The validator whose turn it is to propose a block (the proposer) takes a ready-made block from specialized builders. The deal goes through middlemen, the MEV-Boost relays, and both sides have to trust them.

EIP-7732 builds this separation into the protocol itself. It is called enshrined proposer-builder separation, or ePBS. The proposer includes the builder's commitment in the block, the builder then reveals the block's contents, and the network itself handles the payment to the proposer. A dedicated committee of validators attests whether the builder revealed the block and its blob data on time. According to ethereum.org and CoinCentral, the window for propagating block data grows from about 2 seconds to about 9. That headroom is what lets the network handle larger blocks.

Block-level access lists

EIP-7928 adds to every block a list of the accounts and storage slots its transactions touch (block-level access lists, BALs). When a client knows in advance which data it will need, it can read from disk in parallel and verify parts of the block at the same time instead of strictly one after another. This is the second pillar of future throughput growth.

New gas prices

Gas is the unit Ethereum uses to measure the work a transaction does. Glamsterdam recalculates how much gas different actions cost so that prices better reflect the real load on the network. The main changes from the foundation's announcement:

The 71% figure comes from ethereum.org: the base transaction fee is now calculated from the resources a transaction actually uses rather than one flat rate for everyone. A transfer to a new, empty address gets a surcharge because it grows the network state that every node stores.

The familiar "21,000 gas per transfer" stops being a constant. Wallets and services that hardcoded that number will need updates, and the foundation separately warned contract developers who rely on fixed gas limits.

Block gas limit

The gas limit sets how much work fits into one block. According to CoinCentral and Blockonomi, Glamsterdam prepares the network for roughly 200 million gas per block, up from 60 million in recent tests. At the same time, the foundation's announcement says the Prysm and Teku clients keep 60 million by default after activation, and a validator has to switch on 200 million manually. So the limit will rise gradually as validators adopt it.

What else is included

Other notable changes: ETH transfers will emit a log entry (EIP-7708), making it easier for wallets to track incoming payments; the maximum contract size goes up (EIP-7954); the limit on validator exits and consolidations increases (EIP-8061). The last one matters for staking: the exit queue can be long, and a good example of how it works is the story of why MetaMask is exiting thousands of Ethereum validators.

The risk developers warned about

Under ePBS a builder first wins the auction for a block and only then reveals its contents. On Sepolia this can be abused. Test ether is free, so an attacker can spin up many disposable builders, place high bids, win the auctions and never publish the blocks. A consensus client developer known as Potuz described the scenario bluntly: a thousand rotating builders, high bids and no payloads, adding that "any teenager can do this."

Real money is not at risk: there is no real ETH on Sepolia. But such an attack could halt activity on the testnet and delay testing of the upgrade. According to CoinCentral, client protections may only kick in after several failed payloads, and developers need a way to ban specific builders. The timeline adds pressure too: client releases for Sepolia were due by September 29, leaving seven days for review instead of the usual two weeks. Both CoinCentral and Blockonomi report this.

What ETH holders should do

Nothing. The Ethereum Foundation states plainly that mainnet users and ETH holders don't need to do anything. Ethereum.org adds that there is no need to convert or "upgrade" your ETH and that balances stay the same. You don't need to move your coins anywhere, either now or after the mainnet launch.

News about hard forks always attracts scammers. If someone writes to you about a "token migration," "swapping ETH for the new version" or asks you to connect your wallet to a site to "prepare your address for Glamsterdam," it's a scam. Never share your seed phrase. Only people who run their own node or validator need to update software: before activation they need new versions of both clients.

What changes for fees and speed

• Fees. In gas terms, plain transfers get cheaper while creating new accounts and contracts gets more expensive. The dollar amount also depends on demand for block space and the ETH price, so nobody promises an exact number. A higher gas limit adds room in blocks, which, all else being equal, eases pressure on fees.
• Speed. A block will still come every 12 seconds: Glamsterdam does not shorten the slot. The upgrade lays the groundwork for more transactions in each block, not for more frequent blocks.
• Timing. While the upgrade is being tested on Sepolia and Hoodi, nothing changes on mainnet.

Shorter slots and finality in seconds are longer-term plans. We covered them in our breakdown of how Ethereum plans to become a world computer by 2030. Developers name Hegotá as the next hard fork after Glamsterdam, expected in 2027.

How to get ETH

The hard fork requires no action from holders, so there is no reason to change your ETH plans because of Glamsterdam. If you want to hold ETH in your own wallet, you can buy ETH with bitcoin without registration. VertEXchange doesn't ask for an account, email or phone number, and the ether goes straight to your address. And if you decide to lock in your result in bitcoin, you can swap ETH to BTC the same way.