Ethereum Glamsterdam Upgrade: Roadmap, Testing & Key Changes
Ethereum is about to get its biggest structural overhaul since the Merge.
The EIP-7773 Upgrade is now deep into devnet testing, and it is set to rewrite how blocks get built, verified, and priced on the base layer.
This guide breaks down the full roadmap, the current testing timeline, and every key change developers, validators, and everyday ETH holders need to track.
Key Takeaways
The Ethereum Glamsterdam Upgrade combines "Amsterdam" (execution layer) and "Gloas" (consensus layer) into one coordinated hard fork.
Mainnet activation is targeted for Q4 2026, with a Sepolia testnet fork scheduled for October 6, 2026.
The headline feature, enshrined in the Proposer-Builder Separation (ePBS, EIP-7732), stretches Ethereum's block propagation window from 2 seconds to roughly 9 seconds.
Block-Level Access Lists (EIP-7928) unlock parallel transaction processing and faster node syncing.
Everyday ETH transfers could get up to 71% cheaper once Glamsterdam ships, thanks to EIP-2780.
What Is the Ethereum Glamsterdam Upgrade, and Why Does It Matter?
The EIP-7773 Upgrade is the network's next scheduled hard fork, following directly after Fusaka.
Where Fusaka focused on foundational refinements, Glamsterdam is built to scale Ethereum's Layer 1 by reorganizing how the protocol creates and verifies blocks.
Its name is a portmanteau: "Amsterdam" refers to the execution layer, named for a past Devconnect location, while "Gloas" is the consensus layer piece, named after a star.
Together, the Glamsterdam upgrade advances two roadmap objectives core developers call "Scale L1" and "Scale Blobs."
In short, this upgrade matters because it removes structural bottlenecks limiting how much data Ethereum's base layer can safely process, without sacrificing the decentralization that keeps home staking accessible.
What Is the Official Ethereum Glamsterdam Upgrade Roadmap for 2026?
Ethereum's current roadmap places the EIP-7773 Upgrade on the following track:
Devnet testing (current phase): Core developers run the full set of scheduled EIPs together on private networks, iterating on block-building and gas-pricing interactions.
Public testnet, Sepolia (October 6, 2026): The next confirmed milestone, moving the upgrade from closed devnets to a public testing ground.
Longer-running testnets: Once Sepolia proves stable, the fork moves toward additional networks before the mainnet.
Mainnet activation (targeted Q4 2026): No exact date is locked in; the Ethereum Foundation says the timeline depends on how testnets hold up.
This staged rollout reflects how large the Glamsterdam hard fork is.
Developers call it one of the most ambitious upgrades since the move to proof-of-stake.
How Is the Ethereum Glamsterdam Upgrade Being Tested on Devnets?
Testing for the EIP-7773 Update follows a structured process refined across previous hard forks:
Individual EIP testing: Each proposed EIP is first validated in isolation.
Combined devnet runs: Scheduled EIPs are bundled and run together on iterative devnets, catching interactions that isolated tests would miss.
Performance and hardening review: Client teams assess how combined changes affect sync speed, hardware load, and state growth.
Public testnet fork: Once devnet results stabilize, the upgrade graduates to Sepolia on October 6, 2026.
Mainnet readiness sign-off: Client teams release Glamsterdam-supporting versions are marked high priority before the final fork date is confirmed.
Because this Glamsterdam Update touches both the execution and consensus layers, node operators and stakers will need to update both client types to stay synced after activation.
What Are the Key Technical Changes in the Glamsterdam Upgrade?
Several proposals are scheduled for inclusion in the EIP-7773 Update, grouped around three main goals: faster parallel processing, expanded capacity, and long-term network sustainability.
Enshrined Proposer-Builder Separation (ePBS, EIP-7732): Builds the proposer-builder relationship directly into the protocol, removing reliance on off-protocol relays and extending the propagation window from 2 to about 9 seconds.
Block-Level Access Lists (BALs, EIP-7928): Maps every account a block's transactions will touch before execution begins, enabling parallel disk reads and executionless syncing for new nodes.
State creation gas cost increase (EIP-8037): Introduces a fixed cost per state byte, targeting a predictable state growth rate of roughly 120 GiB per year.
Reduce intrinsic transaction gas (EIP-2780): Cuts the base fee on simple ETH transfers by up to 71%, making everyday payments cheaper.
Increase exit and consolidation churn (EIP-8061): Lets staking exit capacity scale with total ETH staked instead of a fixed cap, speeding up validator withdrawals roughly fourfold.
Additional proposals under consideration for the Glamsterdam hard fork include a larger 64 KiB contract size limit, mandatory ETH transfer logs, and a deterministic factory predeploy for consistent multi-chain wallet addresses.
How Will the Glamsterdam Upgrade Affect Validators and Developers?
For stakers, the EIP-7773 means faster exits, a more balanced builder-selection process, and the need to run updated clients ahead of activation.
Validators should track testnet announcements and rehearse the Update on Sepolia before mainnet day.
For developers, existing smart contracts will keep functioning normally after Glamsterdam, though gas accounting changes mean reviewing deployment costs tied to new state-creation pricing.
A larger contract size limit and native ETH transfer logs also open room for more complex, easier-to-track applications.
Expert Opinion
Analysts tracking Ethereum's protocol roadmap generally view the EIP-7773 as a turning point for Layer 1 scaling rather than a routine maintenance fork.
By enshrining proposer-builder separation and introducing block-level access lists, the network addresses two long-standing architectural constraints at once, setting up a credible path toward higher gas limits without pushing hardware requirements out of reach for home stakers.
The extended testing timeline, moving from combined devnets into a confirmed Sepolia fork before any mainnet commitment, reflects a deliberately cautious approach given the scale of changes involved.
Because Glamsterdam touches both execution and consensus layers at once, thorough public testnet validation will likely matter more for this fork than for several recent Ethereum upgrades combined.
Disclaimer
This article is for informational purposes only and does not constitute financial or investment advice. Upgrade timelines, included EIPs, and technical specifications remain subject to change until the meta EIP is finalized. Readers should verify the latest status directly through official Ethereum Foundation channels before making any decisions related to staking, development, or ETH holdings.
