Glamsterdam Is Live on Sepolia, but the 200M Gas Limit Isn’t

Home » Glamsterdam Is Live on Sepolia, but the 200M Gas Limit Isn’t

October 7, 2026 0

Quick answer: Ethereum’s Glamsterdam upgrade activated on the Sepolia testnet on October 6, 2026, at 13:53:36 UTC (epoch 353,024), bundling 25 proposals including enshrined proposer-builder separation (EIP-7732) and block-level access lists (EIP-7928). Plenty of headlines said the gas limit jumped from 60 million to 200 million. It didn’t, at least not by itself. A fork makes a higher limit safe to run; validators and client defaults decide how fast the network climbs there. One tracker measured about 64.2 million an hour after activation. Mainnet has no date.

That gap between the headline and the chain is the useful part of this story. The fork happened, it worked, and the scaling claim attached to it is still a test in progress. Here’s what changed, what hasn’t, and what to watch before anyone prices a mainnet date into anything.

What actually happened on October 6

The fork went live at slot 11,296,768, right on the schedule the Ethereum Foundation announced on September 17. That’s worth noting on its own. Glamsterdam originally targeted a Sepolia launch on August 3, then slipped through a string of devnets that turned up consensus bugs, as we covered in our earlier look at the upgrade’s security snag. Hitting the October 6 time to the second counts as a small win for a process that had missed two deadlines.

The package combines an execution-layer track (Amsterdam) and a consensus-layer track (Gloas). Reports put the total at 25 EIPs: 18 core and 7 other. Three do most of the heavy lifting:

EIP-7732 (ePBS): builds the proposer-builder split into the protocol itself, so builders commit to a payload before revealing it and validators get more time to verify. The payload propagation window stretches from roughly 2 seconds to about 9, according to Ethereum.org.
EIP-7928 (block-level access lists): blocks list up front which accounts and storage slots they touch, so nodes can read from disk in parallel and run non-conflicting transactions side by side.
EIP-8037 and EIP-8038 (gas repricing): state creation and certain storage accesses get repriced to better match what they cost nodes to carry.

Client teams had shipped Sepolia-compatible releases in the run-up, including Prysm, Teku and Lodestar on the consensus side and Geth, Besu, Reth and Erigon on the execution side. Lighthouse and Grandine were still at release-candidate stage when the Foundation’s table was last reported on, so check your own client’s status rather than assuming.

The 200 million gas question

Here’s where reporting splits. Several outlets wrote that Glamsterdam raised Sepolia’s gas limit from 60 million to 200 million. CryptoTicker’s on-chain check, an hour after the fork, found something different: about 64.2 million, and moving up slowly.

Why? Ethereum’s block gas limit isn’t a number a hard fork sets. Each proposer can nudge it up or down by at most 1/1,024th per block, and the network drifts toward whatever its validators signal. According to CryptoTicker, the 200 million figure in the Foundation’s announcement was a configuration recommendation for the Prysm and Teku validator programs, not a value written into the upgrade specification. KuCoin’s pre-fork briefing said much the same: Prysm 7.2.0 and Teku 26.9.1 default to 60 million after activation, and anyone proposing at 200 million has to set that explicitly. Prysm later shipped version 7.2.1, which defaults to the higher setting.

CryptoTicker estimated that at the pace it measured, roughly 18,600 gas added per block, reaching 200 million would take about a day. Treat that as one outlet’s back-of-envelope figure, not a forecast. It depends entirely on how many validators run updated defaults.

Imagine you run a few validators from a home setup and updated to Prysm 7.0 last month. You’d probably see the fork go through fine, and your node would keep proposing blocks at the old 60 million ceiling until you changed something. Nothing breaks. You just aren’t part of the experiment yet. Multiply that by thousands of operators and you can see why the limit climbs gradually instead of snapping to a new number.

Why a bigger gas limit isn’t the same as cheaper fees

It’s tempting to read 200 million as “fees drop by two thirds.” That’s not how it works. A higher limit gives each block room for more computation. Fees depend on how much demand is chasing that room. If activity is light, the base fee is already low; if demand grows to fill the extra space, fees can stay put.

The better framing is headroom. When we looked at what happened to fees nine months after Fusaka, the lesson was that capacity upgrades change the ceiling, and market behavior decides what you pay. Glamsterdam is the same story with a bigger ceiling, plus a repricing that moves costs around. Ethereum.org says standard ETH transfers could become up to 71 percent cheaper under the new accounting. It also says state creation will cost more, calibrated to a target of roughly 120 GiB of state growth a year. Cheaper for some actions, pricier for others.

What the testnet fork can and can’t tell us

Sepolia is a deliberately forgiving environment. Its test ETH has no market value, and its validator set is permissioned, meaning operators can step in by hand if something goes sideways. That’s useful for catching client bugs. It tells you much less about behavior under real economic pressure.

The builder-abuse worry we flagged in late September is a good example. Consensus developer Potuz warned on September 17 that anyone could spin up many throwaway builders on a free testnet, win block-building auctions, and then withhold payloads. On mainnet, that costs real money. On Sepolia it costs nothing. As far as we could find, no universal fix was agreed before the fork, and we haven’t seen reports of it happening since activation. That’s an absence of evidence in a short window, not proof it can’t happen.

Developers also have a heavier set of tests ahead. Devnet-11 ran roughly 84,000 validators across multiple clients before the public fork, which is a far bigger stress test than the thousand-node Devnet-9 that failed to finalize in early September. Sepolia adds public traffic and real third-party tooling. Hoodi, the second public testnet with an open validator set, is closer to mainnet conditions and still has to happen first.

What’s still unconfirmed

The honest list is longer than the confirmed one:

Hoodi date. The Foundation hasn’t announced one. A pre-fork Blockonomi report floated October 27 as provisional; we couldn’t confirm that from a second source, so don’t treat it as scheduled.
Mainnet date. The roadmap says Q4 2026 and the Foundation says the date isn’t confirmed. One community member quoted by The Crypto Times guessed five to nine weeks, which is speculation. Given that Hoodi hasn’t been dated, a late-year mainnet looks tight, though that’s our reading, not an official position.
Final mainnet gas limit. Cryptobriefing reports the final parameters haven’t been decided, and there are no immediate changes to mainnet’s limit. It’s still around 60 million today.
Contract compatibility. CCN reports testing found some existing smart contracts could break under revised gas assumptions, though most are unaffected. Wallets, gas estimators and indexers will need updates.

What this means if you hold ETH or use layer-2s

For most people: nothing, today. Nobody has to do anything with their ETH. Ethereum.org is blunt about this, and about the risk that comes with any big upgrade: anyone telling you to “upgrade” or “migrate” your ETH is trying to scam you. Upgrades happen at the protocol level.

For layer-2 users, the story is indirect. Rollups post their data to Ethereum, so more base-layer room can eventually feed through to cheaper operation. Our explainer on how optimistic and ZK rollups work covers that link. But it’s eventual and conditional, and a testnet at 64 million gas isn’t evidence of any of it yet.

For traders, the price context was unremarkable. ETH traded near $2,690 to $2,712 on October 6, according to FXStreet and CryptoTicker, roughly flat on the week. A testnet fork rarely moves markets, and if you’re tempted to trade around an upgrade narrative, remember how often the dates have slipped.

For node operators and stakers, the checklist is practical. Confirm your execution and consensus clients are on Sepolia-compatible releases if you run testnet validators, watch your client’s default gas-limit setting, and read the release notes before assuming defaults match the headline.

A fair read on the milestone

It’s easy to oversell a testnet fork, and just as easy to wave it off. The reasonable view sits between the two. A fork that activated cleanly, on schedule, with 25 EIPs and a rebuilt block-building pipeline, is real progress after a rough devnet stretch. Toni Wahrstätter of the Ethereum Foundation called Glamsterdam the network’s biggest throughput increase since launch, a claim the testnet will have to back up with sustained numbers.

But the real evidence arrives in the next few weeks: how high the limit actually climbs, whether blocks stay finalized under load, whether the builder-abuse scenario shows up, and whether Hoodi gets a date. Those are the signals worth tracking, and they’re more informative than any single headline number.

Frequently asked questions

Did Glamsterdam launch on Ethereum mainnet?

No. It activated only on the Sepolia testnet on October 6, 2026. Hoodi comes next, and mainnet has no confirmed date.

Is the Ethereum gas limit now 200 million?

Not on mainnet, and not as a fixed rule on Sepolia either. One tracker measured about 64.2 million an hour after the fork. The 200 million figure is a testing target that validators opt into through client settings.

Will Glamsterdam lower Ethereum gas fees?

It may add headroom, and some actions, such as simple ETH transfers, are expected to get cheaper under the new accounting. Others, like creating new state, will cost more. Actual fees still depend on demand.

Do I need to do anything with my ETH?

No. Balances aren’t affected, and Ethereum.org warns that anyone asking you to upgrade your ETH is attempting a scam. Only node operators and stakers need to update their client software.

Key takeaways

Glamsterdam went live on Sepolia on October 6, 2026 at epoch 353,024, with 18 core and 7 other EIPs.
The 200 million gas figure is a validator-side target. One tracker saw about 64.2 million after an hour, and Prysm 7.2.1 defaults to the higher setting.
A higher limit is headroom, not a guaranteed fee cut.
Hoodi and mainnet dates remain unconfirmed; treat unofficial estimates cautiously.
Sepolia is a forgiving testbed, so the builder-abuse concern and contract-compatibility risks still need real-world testing.

Disclaimer: This article is for educational purposes only and isn’t financial advice. Crypto assets are volatile and carry risk of loss. Do your own research before making any decision.

Want to keep following how Ethereum’s roadmap plays out in practice? Our earlier pieces on the Glamsterdam builder-abuse risk and the Fusaka fee retrospective are good next reads, and you can subscribe to FiscalFrontier for updates when Hoodi gets a date.