Ethereum’s biggest protocol overhaul in years moves into its final development stage

Jun 16, 2026, 2:48 p.m. 2 min read(Adi Goldstein/Unsplash)SummaryEthereum developers have entered the final development phase of Glamsterdam, running devnets with all planned EIPs before moving to testnets. The upgrade, expected in the second half of the year, is being described as one of the network’s biggest changes since the Merge.Ethereum developers are entering the final stretch of work on Glamsterdam, the network's next major upgrade, as teams begin testing a version of the fork that includes the planned protocol changes.Developers are currently running developer networks, or "devnets", early testing environments used by Ethereum developers to trial new code and protocol changes before they reach public testnets, containing the full suite of Ethereum Improvement Proposals (EIPs) slated for the upgrade, marking what they describe as the final phase before the codebase is hardened and deployed to public testnets."We're working on devnets with all the EIPs in them right now," said Parithosh Jayanthi, a core developer at a devops engineer at the Ethereum Foundation. "This is the last phase before we work on hardening and then shipping the testnets. There's no fixed timeline, but we've made massive progress."While a firm activation date for the upgrade has yet to be determined, Glamsterdam is currently expected to go live during the second half of the year.The upgrade is shaping up to be one of Ethereum's most ambitious since the network's transition to proof-of-stake in 2022. Jayanthi described Glamsterdam as "probably the largest fork we've had since the Merge," adding that it will "change a lot of assumptions about Ethereum and set us up for much more scaling in the future."Among the headline features are enshrined Proposer-Builder Separation (ePBS), formally tracked as EIP-7732, and Block-level Access Lists (EIP-7928).ePBS would bring into Ethereum's core protocol a separation between the entities that build transaction blocks and those that propose them. Today, that process largely relies offchain, where there are additional trust assumptions and centralization concerns. By moving the mechanism onchain, developers hope to reduce opportunities for manipulation related to maximal extractable value, or MEV.Another major proposal, Block-level Access Lists, would allow blocks to declare in advance which accounts and smart-contract data they intend to access. The change would enable Ethereum clients to preload information more efficiently, helping make block execution faster, more predictable and easier to optimize.Beyond those headline proposals, Glamsterdam also includes a sweeping set of gas repricings that could significantly alter the economics of using Ethereum.“This will majorly change the cost of actions on Ethereum. High-level compute gets cheaper and state gets more expensive."The repricings are intended to make Ethereum's fee structure more accurately reflect the resources consumed by different operations while also making the network easier to scale with zero-knowledge proving systems, according to Jayanthi.Developers are currently focused on continued testing, finalizing specifications and conducting outreach to the broader Ethereum community about the implications of the repricing changes."Mostly testing, finalizing specs, outreach to the community about repricings and then shipping it," Jayanthi said.Read more: Ethereum’s ‘Glamsterdam’ upgrade aims to fix MEV fairness12345678910