Ethereum Glamsterdam Upgrade: Gas Fees Could Drop 71%

Ethereum’s biggest protocol shake-up since the 2022 Merge just moved its target date to the end of August 2026, and this time the numbers behind it are concrete. The upgrade is called Glamsterdam — a mash-up of Gloas and Amsterdam, the city where the next Devconnect gathering happens — and it touches almost everything about how the network processes transactions, from how blocks get built to what a simple transfer costs you at the point of sending.

When I looked into what’s actually inside this upgrade, two numbers jumped out. Gas fees for a simple ETH transfer could drop by up to 71%. The network’s baseline gas limit is set to jump from around 60 million to a 200-million floor. That’s not a tweak. That’s Ethereum trying to solve the “it’s too expensive to use” complaint that’s followed it since 2021, and it’s arriving at a moment when Layer 2 rollups have already pulled a huge share of everyday activity off mainnet.

What Glamsterdam Actually Changes

Every Ethereum upgrade bundles a handful of Ethereum Improvement Proposals, or EIPs, into one coordinated hard fork. Glamsterdam centres on two headline changes: enshrined Proposer-Builder Separation, known as ePBS, and Block-Level Access Lists, known as BALs. Both sound like plumbing. Both change what it feels like to actually use the network.

Right now, block building and block proposing are separated informally, through a system called MEV-Boost that most validators bolt on voluntarily. Glamsterdam bakes that separation directly into Ethereum’s core protocol rules. Once it’s enshrined, validators no longer rely on third-party relay software to get the benefits of separating who builds a block from who proposes it. Fewer moving parts. Fewer points where a relay outage can disrupt block production network-wide, which has happened more than once in Ethereum’s post-Merge history.

ePBS: Splitting Block Building From Consensus

ePBS matters because it stretches Ethereum’s data propagation window from roughly 2 seconds to about 9 seconds. That sounds like it should slow things down. It actually does the opposite for throughput, because block builders get more breathing room to assemble complex blocks without the network stalling while they wait for data to spread.

UK investors keep asking about this because it’s the mechanism that finally unblocks higher transaction throughput without compromising how decentralised block production stays. Ethereum’s engineers have spent three years arguing about how to do this safely. Glamsterdam is the answer they’ve settled on, after several earlier proposals were shelved for concentrating too much power in a handful of professional block builders.

The design isn’t uncontested. Some researchers argue a 9-second window still favours well-resourced builders who can afford faster infrastructure over hobbyist validators. The Ethereum Foundation’s position is that the throughput gains outweigh that risk, provided BALs keep execution costs low enough that smaller builders stay competitive.

Block-Level Access Lists Explained

BALs are the quieter half of the upgrade, and arguably the more useful one for anyone actually paying gas fees. A block-level access list declares, in advance, exactly which accounts and which pieces of smart contract data a block intends to touch. Client software can preload that data instead of fetching it on the fly.

The practical effect: block execution gets faster and far more predictable. Validators spend less compute time guessing what a transaction needs and more time just running it. That predictability is a big part of why the Ethereum Foundation feels confident setting a 200-million gas limit floor — a jump that would have been reckless without BALs smoothing out execution first.

Think of it like a delivery driver getting a full manifest before leaving the depot, rather than working out the route stop by stop. Less guesswork. Fewer wasted trips. Applied across millions of blocks a year, that efficiency compounds into real fee savings, and it’s the kind of unglamorous engineering work that rarely makes headlines but ends up mattering more than the flashier features.

The Gas Fee Numbers, in Plain English

Here’s the part that actually affects your wallet. Glamsterdam cuts the intrinsic gas floor on transactions — the baseline cost every transfer pays regardless of complexity. Simple ETH transfers between existing accounts are projected to get up to 71% cheaper. Complex smart contract calls, the kind that power DeFi swaps and NFT mints, see reductions reported as high as 78.6% in some test environments.

Nobody should treat those figures as guaranteed. Testnet numbers and mainnet reality rarely match exactly. But even a conservative real-world outcome — say, half those projected savings — would mark the cheapest sustained gas environment Ethereum has had in years. For context: a swap that costs £8 in gas today could realistically drop toward £3-4 once Glamsterdam settles in on mainnet, and a basic transfer that costs 40p could fall to little more than 10p.