Ethereum's first generalized devnet for the Glamsterdam hard fork went live the week of April 14, 2026, merging two previously separate testing environments — one for Enshrined Proposer-Builder Separation (ePBS) and one for Block-Level Access Lists (BALs) — into a single coordinated network. The ...
"I think in 2026, I would expect to see 100 million fairly soon. Anything beyond that is probably just too speculative." — Gary Schulte, Senior Engineer, Besu Client (Hyperledger)
Ethereum's first generalized devnet for the Glamsterdam hard fork went live the week of April 14, 2026, merging two previously separate testing environments — one for Enshrined Proposer-Builder Separation (ePBS) and one for Block-Level Access Lists (BALs) — into a single coordinated network. The milestone marks the first time all Glamsterdam components have coexisted on the same chain.
The upgrade, anchored by EIP-7732 (ePBS) and EIP-7928 (BALs), targets a 78% reduction in Layer 1 gas fees, a gas limit increase from the current 60 million to 100–200 million per block, and a throughput trajectory toward 10,000 TPS. It would also move block construction from off-chain relay infrastructure — where two to three builders currently control roughly 75–80% of production — directly into the protocol. The Ethereum Foundation has characterized the June mainnet target as aspirational; Q3 2026 is the more realistic window.
If executed, Glamsterdam would represent Ethereum's most consequential protocol change since the Merge in September 2022. It also carries material implementation risk: ePBS fundamentally alters consensus-layer coordination, academic research suggests it may amplify builder profit concentration, and the "free option problem" could affect approximately 6% of blocks during high-volatility periods.
The Ethereum Foundation's Checkpoint #9 blog post, published April 10, 2026, confirmed that separate devnets for ePBS (epbs-devnet) and BALs (bals-devnet) would be merged into a single generalized Glamsterdam devnet. That devnet launched the following week.
Development has been described by the Foundation as "slow but steady." ePBS remains the primary bottleneck, requiring what developers call "partial blocks" and two-party coordination between block proposers and builders — a fundamental change to how the consensus layer operates. Client developers have described these as "expectedly difficult problems" with "predictable progress," according to the Foundation checkpoint.
The path from generalized devnet to mainnet follows a defined sequence: client releases, security audits, public testnet deployments on Holesky and Sepolia, and finally mainnet activation. Tomasz Stańczak, co-director of the Ethereum Foundation, has indicated the gas limit would increase to 100 million in H1 2026, with a doubling to 200 million following ePBS deployment. Stańczak has suggested gas limits could reach 300 million by year-end, though Besu client engineer Gary Schulte has characterized anything beyond 100 million as "too speculative."
A Q2 2026 mainnet launch appears improbable given the current pace. Q3 2026 is the working estimate.
Glamsterdam is a combined hard fork updating both the Execution Layer (Amsterdam) and Consensus Layer (Gloas). Two EIPs anchor the release.
EIP-7732: Enshrined Proposer-Builder Separation (ePBS)
Currently, Ethereum validators propose blocks, but the actual transaction packaging runs through external relay infrastructure — primarily MEV-Boost, operated by Flashbots and others. EIP-7732 moves this separation directly into the protocol. Builders submit cryptographic commitments on-chain without revealing transaction contents until the commitment locks. The protocol handles the auction and payload verification autonomously, replacing trust-based relay intermediaries with consensus-enforced mechanisms.
As Ethereum researcher Ladislaus von Daniels explained, ePBS "decouples block validation from block execution and ships another flavor of delayed execution." A new Payload Timeliness Committee is introduced to validate block construction.
EIP-7928: Block-Level Access Lists (BALs)
BALs address what Consensys senior blockchain engineer Gabriel Trintinalia called "the biggest bottleneck we have" — sequential disk reads during transaction execution. Blocks must pre-declare which accounts and storage slots they will access during construction. This allows nodes to pre-fetch state data and execute non-conflicting transactions in parallel.
According to Trintinalia: "With Block Access List, we are getting all the state that changes from transaction to transaction, and you are putting that information in the block." The estimated near-term throughput improvement from parallel execution is 10–30x.
Supporting EIPs
The upgrade also includes EIP-7904 (general gas repricing based on modern hardware benchmarks), EIP-7954 (increased maximum contract size), EIP-8037 (higher state creation costs), and EIP-8038 (increased cold storage access costs).
EIP-7904 recalibrates gas costs to reflect current hardware capabilities rather than the assumptions baked into Ethereum's original fee schedule. The repricing delivers a projected 78.6% reduction in gas fees across transaction types.
At current gas prices, users paying $4–8 per swap on L1 would see costs drop proportionally. Combined with the gas limit increase from 60 million to 100 million initially — and potentially 200 million post-ePBS — the effective capacity of each block expands substantially.
Ethereum Foundation co-founder Vitalik Buterin has advocated for a "5x gas limit increase together with 5x gas cost increase for operations that are relatively inefficient," suggesting a targeted repricing approach rather than a blanket reduction.
The gas limit increase is phased deliberately. At 100 million, throughput scales to approximately 3–5x current levels. At 200 million with ePBS operational and parallel execution enabled, the network targets approximately 10,000 TPS — though this figure represents a theoretical ceiling, not a guaranteed sustained rate.
An estimated 80–90% of Ethereum blocks currently flow through off-chain relay infrastructure, with Flashbots MEV-Boost handling the majority. Data from relay monitoring shows the top three builders control over 75% of PBS blocks. This creates three structural risks:
ePBS addresses these by making builder commitments cryptographically binding within the consensus layer. Block construction becomes auditable on-chain. Relays like MEV-Boost would no longer be required for the block-building pipeline, though they may persist in diminished roles.
Flashbots has been developing MEV-Share, which redistributes a portion of extracted value back to users whose transactions generated it. This approach operates orthogonally to ePBS and could coexist with on-chain block building.
ePBS does not automatically solve builder concentration. Academic research has raised specific concerns.
A study modeling ePBS economics found that the mechanism "significantly amplifies profit and content centralisation" among builders, because sophisticated builders with access to private order flow maintain structural advantages regardless of whether the auction runs on-chain or off-chain. The research concludes that a small number of efficient builders capture most value via MEV-driven auctions.
The "free option problem" is a second identified risk. After a builder commits to a block, they retain the option to withhold it if market conditions change. Research estimates this affects approximately 0.82% of blocks on average under an 8-second option window, rising to approximately 6% during high-volatility periods.
Vitalik Buterin has acknowledged these risks directly. In a March 2026 post, he outlined proposals for FOCIL (Forward Obligatory Commitment to Inclusion Lists) — a mechanism that would randomly select participants to ensure certain transactions must be included in blocks — and encrypted mempools to prevent frontrunning and sandwich attacks. These are not part of Glamsterdam but are targeted for the Hegota fork in H2 2026.
Glamsterdam does not displace Layer 2 networks. Even at 200 million gas per block, L2s remain cheaper for cost-sensitive activity and offer sub-second finality that L1 cannot match at its 12-second block time.
The upgrade does strengthen the rollup ecosystem in two ways. First, the blob count per block may increase to 72 or more, giving optimistic and ZK rollups substantially more room to publish compressed transaction data. This could push rollup transaction costs to fractions of a cent while maintaining Ethereum's security guarantees.
Second, parallel execution on L1 improves batch settlement efficiency. Rollups submitting proofs and data to L1 benefit from reduced congestion and faster inclusion, improving user experience across L2 applications including decentralized exchanges, lending protocols, and cross-chain bridges.
The economic tension identified in earlier analysis — Ethereum's record 200.4 million transactions in Q1 2026 generating near-record-low fee revenue — is not resolved by Glamsterdam. Lower L1 fees may drive more activity back to L1 from L2s, but the fee-per-transaction trend continues downward.
Glamsterdam positions Ethereum against parallel-execution competitors. Solana's Sealevel scheduler delivers 1,000–1,500 TPS with approximately 400ms block times. Monad targets 10,000+ TPS with optimistic execution at similar latencies. Ethereum's parallel execution, via pre-declared access lists, takes a different architectural approach — more conservative but maintaining the existing validator set of 500,000+ nodes.
| Metric | Ethereum (Post-Glamsterdam) | Solana | Monad | |---|---|---|---| | Target TPS | ~10,000 | 1,000–1,500 | 10,000+ | | Block Time | ~12 seconds | ~400ms | ~400ms | | Parallelism Method | Pre-declared access lists | Sealevel scheduler | Optimistic execution | | Validator Set | 500,000+ | ~1,900 | TBD |
Ethereum's 12-second block time remains a structural constraint that Glamsterdam does not address. The Fast Confirmation Rule, already deployed or imminent, reduces deposit confirmation to 13 seconds but does not alter base-layer finality for general transactions.
Glamsterdam's devnet merge represents tangible progress toward Ethereum's most ambitious protocol change since the Merge. The technical scope is substantial: moving block construction on-chain, enabling parallel execution, and repricing the gas schedule in a single coordinated fork.
The risks are equally concrete. ePBS introduces consensus-layer complexity that has slowed development. Academic modeling raises questions about whether on-chain auctions will distribute value more equitably or simply formalize existing builder dominance. The phased gas limit approach — starting at 100 million, expanding to 200 million — acknowledges that the system needs to be proven at each threshold.
For users, the near-term implication is clear: if Glamsterdam ships as designed, L1 gas costs drop by roughly 78% and throughput scales meaningfully. For the protocol's economic model, the picture is more ambiguous. Lower fees on a higher-throughput chain may not translate to increased fee revenue for validators or ETH holders — a structural question that Glamsterdam's technical improvements do not answer.