Ethereum’s 200M Gas Test Goes Live: Glamsterdam Pushes Sepolia to a New Scaling Extreme
Ethereum is testing a 200 million block gas limit on the Sepolia testnet as part of the Glamsterdam upgrade, pushing network scaling limits to evaluate validator and client performance.
Ethereum is rolling out a major Layer 1 capacity trial that pushes the Sepolia testnet’s block gas limit to 200 million as part of the Glamsterdam upgrade. This scaling test more than triples Sepolia’s previous limit of 60 million, allowing developers to observe how clients and validators handle increased computational demands per block.
Ahead of the hard fork at epoch 353,024 on October 6 at 13:53:36 UTC, Prysm version 7.2.1 incorporated a pre-defined gas limit schedule. Following the Gloas hard fork, validators running Prysm 7.2.1 automatically adopt the 200 million gas limit setting.
While validators using Prysm 7.2.0 can still join the hard fork, that software version predates the schedule update and defaults to a 60 million limit unless operators manually configure a higher threshold.
Ethereum Tests a Major Expansion in Block Capacity
A block gas limit defines the maximum amount of computation transactions can consume within a single block. Raising this limit allows more payments, token swaps, and smart contract transactions to fit into each block, though higher limits do not automatically translate to reduced transaction fees.
Transaction costs are also influenced by user demand and the specific types of transactions being executed. The new Sepolia threshold exceeds the 60 million mainnet gas limit previously seen on Ethereum.
⚡🔥 TODAY: Ethereum's Sepolia testnet forks to Gloas at 13:53 UTC with a 200M gas limit. pic.twitter.com/cAz9mnHmxw
— Cointelegraph (@Cointelegraph) October 6, 2026
Data gathered from the Sepolia testnet offers valuable insights into client and validator performance, guiding decisions on whether to apply comparable adjustments to the mainnet.
This experiment forms part of Glamsterdam, a combined upgrade encompassing the Amsterdam execution layer and the Gloas consensus layer. Key components designed to enhance Layer 1 capacity include Block-Level Access Lists and a built-in proposer-builder split.
Glamsterdam Devnet 11 previously tested moving the chain capacity from 60 million to 200 million. Conducting the trial on Sepolia enables public testing across a diverse array of validator setups and multiple clients to uncover issues that private testing might miss.
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Expanding Ethereum’s state capacity brings certain drawbacks. To mitigate these risks, the Glamsterdam initiative introduces gas fee adjustments that raise the computational costs associated with specific full node transactions. EIP-8037 increases expenses for generating a new state, while EIP-8038 adjusts account and storage access costs.
Sepolia Test Does Not Mean a 200M Mainnet Gas Limit
The October 6 activation affects solely the Sepolia testnet, not the Ethereum mainnet. Activation dates for Hoodi and the mainnet remain unconfirmed on the Ethereum Foundation’s deployment schedule.
To maintain participation in the upgraded network, Sepolia validators must operate compatible execution and consensus clients. Several consensus clients support the Sepolia network, including Prysm, Lighthouse, Nimbus, Teku, Lodestar, and Grandine.
🛠 @ethereum developers have pushed out a last-minute Prysm update ahead of Tuesday's trial run of the Glamsterdam upgrade on Sepolia. Version 7.2.1 automatically scales the maximum gas per block to 200M, up from the earlier 60M cap.
Had it stayed that way, blocks proposed at… pic.twitter.com/0k4kFYg4JK
— Mpost Media Group (@mpost_io) October 6, 2026
The trial yields insights into how stable large contract sizes are. Furthermore, it helps developers understand the interplay between growing transaction throughput, state size expansion, and Glamsterdam’s updated gas pricing as they prepare for a future mainnet rollout.
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Following the Gloas hard fork upgrade in Prysm version 7.2.1, Sepolia’s default block gas limit becomes 200 million. Operators retain the option to configure alternative limits using proposer settings or other Prysm APIs, including a recommended Prysm API. The mainnet has not been upgraded yet, and any mainnet transitions are scheduled separately while this trial remains experimental.



