The Glamsterdam upgrade is Ethereum’s next major hard fork, and developers planned to take it to its final testnet this week. Instead, on October 22, core developers postponed the Hoodi testnet activation to take a closer look at one gas-pricing change. Here’s what Glamsterdam changes, why it matters for ETH users and builders, and where the timeline stands now.
What is the Glamsterdam upgrade?
Glamsterdam is a combined upgrade to both halves of Ethereum. The name joins Gloas, the consensus-layer fork, with Amsterdam, the execution-layer fork. In practice, it follows the same pattern as earlier upgrades like Dencun and Pectra.
Above all, its main goal is to let Ethereum’s main chain (layer 1) process far more activity safely. To do that, it changes how blocks are built and validated, and it reprices operations that make the network’s state grow. As a result, it paves the way for a gas limit of 200 million, up from 60 million today, which is about 3.3 times more room per block. However, that is a target ceiling, not a guaranteed throughput gain.
The two headline changes: ePBS and block-level access lists
1. Enshrined proposer-builder separation (ePBS, EIP-7732). Today, specialized “builders” assemble most Ethereum blocks and pass them to validators through off-protocol relays. In other words, these relays are trusted middlemen. ePBS moves that handoff into the protocol itself, so validators no longer need to trust a relay. In addition, it gives nodes more time within each slot to receive and check blocks, which is one of the things that limits how big blocks can safely get.
2. Block-level access lists (BALs, EIP-7928). Each block will list the accounts and storage slots its transactions touch. Because clients know in advance what data a block needs, they can load it early and process many transactions in parallel instead of strictly one after another. Consequently, nodes can validate blocks faster, which again supports a higher gas limit.
Other changes in the Glamsterdam upgrade
Beyond the two headline features, the Glamsterdam upgrade bundles more than a dozen smaller EIPs. Below are the ones most likely to affect users and developers, based on the Ethereum Foundation announcement:
| EIP | What it does | Who notices |
|---|---|---|
| EIP-8037 / 8038 | Raises gas costs for creating new state and updates costs for accessing it | Developers; contracts with hardcoded gas |
| EIP-7976 / 7981 | Higher calldata floor and access-list costs | Rollups and heavy data users |
| EIP-2780 | Bases each transaction’s starting gas on the resources it actually uses | Everyone sending transactions |
| EIP-7708 | Plain ETH transfers now emit a log | Wallets, exchanges, block explorers |
| EIP-7954 | Raises the maximum smart contract size | Smart contract developers |
| EIP-8261 | Optional schedule for raising the gas limit toward 200M | Validators and node operators |
Why the Hoodi testnet was postponed
Glamsterdam went live on the Sepolia testnet on October 6, 2026. Next, developers scheduled it to activate on Hoodi, the last testnet before mainnet, on October 26 at 17:42:48 UTC.
However, on the October 22 All Core Developers call (ACDE #248), developers delayed it to investigate how EIP-8037 interacts with existing mainnet contracts (Ethereum Foundation). Researchers found that some contracts with hardcoded gas limits, fixed gas stipends or assumptions about remaining gas could behave differently under the new rules. Importantly, this is a compatibility concern for a small set of contracts, not an exploit on Ethereum today (Crypto Economy). Developers also postponed the planned Hoodi gas-limit increase to 200M.
When will the Glamsterdam upgrade hit mainnet?
There is no mainnet date yet. Before the delay, developers had floated December 1 or December 8, 2026, on the condition that Hoodi went smoothly (KuCoin). Since Hoodi now needs a new date first, those targets are likely to slip. For now, the Ethereum Foundation says it will announce the new schedule separately.
Devcon 8 in Mumbai (November 3–6) is a likely place for fresh signals on timing. We’ll cover it here.
What it means for you
- ETH holders and everyday users: no action needed. The testnet delay doesn’t affect your ETH or wallets.
- Developers: review contracts that rely on fixed gas amounts, and test on Sepolia, where Glamsterdam is already live.
- Stakers and node operators: follow your client team’s releases and make sure no config still schedules the old October 26 Hoodi fork.
- Layer 2 users: more layer-1 capacity could ease fees over time, although calldata repricing may change rollup costs.
For background on how Ethereum already scales, read our guide to Layer 2 solutions on Ethereum, and see how to keep Ethereum transactions secure.
Bottom line
Overall, the Glamsterdam upgrade is Ethereum’s biggest push yet to scale layer 1 directly, through ePBS, parallel-friendly blocks and a path to a 200M gas limit. The Hoodi delay is a normal part of careful upgrade testing, but it does make a December mainnet launch less certain. Meanwhile, keep an eye on the next All Core Developers calls and Devcon 8 for the new schedule.
Disclaimer: This article is for information only and is not financial or investment advice. Cryptocurrencies are volatile and you can lose money. Do your own research before making any investment decision.
