Ethereum Glamsterdam Upgrade Guide 2026
Glamsterdam is Ethereum's next major hard fork, targeting H1 2026 with two headline EIPs that reshape L1 scalability and MEV fairness. EIP-7732 enshrines proposer-builder separation into consensus, moving MEV resistance from off-chain to protocol. EIP-7928 enables parallel transaction execution through block-level access lists. Combined with gas repricing and a 3.3x gas limit increase, Glamsterdam targets 10,000 TPS — up from ~1,000 today. This is the biggest L1 upgrade since The Merge.
1. What Is the Glamsterdam Upgrade?
Glamsterdam is Ethereum's next major consensus layer hard fork, scheduled for H1 2026 (June aspiration). Named after Amsterdam, the city where Ethereum's 2024 Devcon took place, Glamsterdam represents the protocol's most ambitious L1 scaling initiative since The Merge (September 2022). It combines three core innovations: enshrined proposer-builder separation (ePBS), block-level access lists (BALs), and gas repricing — all designed to increase throughput, reduce MEV, and lower transaction costs simultaneously.
Understanding this concept is a prerequisite for making informed decisions in DeFi. Most losses in crypto come from misunderstanding the fundamentals.
The Glamsterdam Headlines (In Numbers)
Gas Limit: 60M → 200M per block (+233%)
Throughput: ~1,000 TPS → ~10,000 TPS (10x)
Gas Costs (EIP-7904): 78.6% reduction for transfers & smart contract calls
Major EIPs: EIP-7732 (ePBS) + EIP-7928 (BALs) + EIP-7904 (gas repricing) + 25+ additional EIPs
Status (April 2026): Final testnet stages; mainnet activation pending ecosystem readiness
Why Glamsterdam Matters
Ethereum has relied on Layer 2 scaling (Arbitrum, Optimism, Base) for most throughput gains since 2022. Glamsterdam flips the narrative: instead of pushing all scaling to L2, it dramatically expands L1's native capacity. This benefits:
- L1 users: 10x cheaper transactions, faster finality, less MEV extraction
- L2 sequencers: Lower settlement costs on L1, enabling even cheaper L2 fees
- DeFi protocols: More efficient arbitrage, better execution quality, reduced sandwich attacks
- Validators: Higher hardware requirements (SSD, RAM) but protocol-level MEV fairness reduces reliance on centralized relays
- Ethereum: Stronger competitive position vs. Solana, Sui, and other high-throughput L1s targeting sub-cent fees
Glamsterdam is not just a performance upgrade. It's a philosophical shift: proving that decentralized consensus can scale to mainstream transaction volumes while maintaining fairness and censorship resistance.
2. EIP-7732: Enshrined Proposer-Builder Separation
EIP-7732 moves proposer-builder separation (PBS) from off-chain infrastructure into Ethereum's consensus protocol. Today, MEV-Boost intermediates between block proposers and builders via centralized or semi-centralized relays. Glamsterdam eliminates that dependency by encoding PBS directly into the consensus layer.
How ePBS Works: The Flow
Slot 0 (Builder Phase): Multiple builders construct blocks and commit to their contents (a cryptographic hash). They submit sealed bids specifying their profit. The proposer sees only the bid amount, not the block contents.
Slot 1 (Reveal Phase): The winning builder (highest bid) reveals their block contents. The proposer includes it in the canonical chain. If the builder fails to reveal, their bid is forfeited, and the second-highest bidder wins.
Why Commit-Reveal Matters
Proposer Censorship Prevention: The proposer cannot see the block contents before committing. They cannot selectively exclude transactions or reorder without rebuilding the entire block (economically irrational).
Builder Competition: Builders bid competitively for the right to propose. Profit-maximizing builders pack blocks efficiently, driving fees down for users.
MEV Redistribution: Instead of relays capturing MEV, profit flows to builders (rewarding efficient block construction) and proposers (who sell the slot to the highest-bidding builder). Users benefit via lower inclusion fees.
Before vs After ePBS: The Relay Problem Solved
| Aspect | Today (MEV-Boost) | After ePBS |
|---|---|---|
| Infrastructure | Off-chain relays (Lido, Flashbots, etc.) | In-protocol consensus |
| Proposer Trust | Trusts relay not to sandwich or censor | Cryptographic guarantees; no trust required |
| Censorship Resistance | Relay could block transactions selectively | Protocol-level protection; economically impossible |
| MEV Capture | Relays extract fees from proposers | Competitive auction; proposers capture full MEV premium |
| Decentralization | Relay consolidation risk (few large relays) | Many independent builders; lower barriers to entry |
Real-world impact: A proposer today using Lido's relay must trust Lido not to censor transactions or sandwich orders. With ePBS, that trust is eliminated. The proposer simply sees: "Builder X bids 10 ETH, Builder Y bids 9 ETH. I take the higher bid." The block contents are irrelevant to their decision.
3. EIP-7928: Block-Level Access Lists
Today, Ethereum executes transactions serially. Transaction 1 → Transaction 2 → Transaction 3. This is the #1 throughput bottleneck. Even with perfect consensus and networking, a single CPU core executing transactions sequentially is a hard limit.
EIP-7928 (Block-Level Access Lists) solves this by pre-declaring which accounts and storage slots each transaction will touch. This metadata allows the execution layer to safely parallelize transactions across multiple CPU cores.
How Parallel Execution Unlocks 10x Throughput
Consider a block with 10 transactions:
Tx 2: Uniswap swap (touches: UniPool.reserves, Token.balances)
Tx 3: Transfer from Charlie to Dave (touches: Charlie.balance, Dave.balance)
... and so on
With BALs, the execution client knows upfront:
- Tx 1 & Tx 3 don't conflict (different accounts) → execute in parallel on cores A & B
- Tx 2 touches UniPool, which no other Tx touches → execute independently on core C
- Result: 3 transactions complete in 1 time unit instead of 3
Why This Is a Game-Changer
Current Ethereum uses ~4 cores per validator; Glamsterdam will enable utilization of 16-32 cores. A 16-core machine can execute 16 non-conflicting transactions simultaneously. This isn't theoretical — Solana has proven parallel execution works at scale.
Combined with higher gas limit and repricing, 10,000 TPS becomes achievable on L1.
Access List Metadata
In Glamsterdam, each transaction must declare:
- Accounts it will write to
- Storage slots it will access (read or write)
- Optional: Accounts it only reads
If a transaction touches undeclared state, it reverts. This incentivizes accurate declarations and prevents hidden dependencies. Builders optimize by batching compatible transactions.
4. Gas Repricing & Fee Reductions (EIP-7904)
EIP-7904 reprices gas to align costs with actual computational resources consumed. Today's gas costs are ~10 years old, calibrated for 2015-era hardware. They don't reflect modern CPU performance.
The Repricing Logic
Memory & storage operations (the expensive stuff) stay roughly the same. Arithmetic, hashing, and cryptographic operations (cheap on modern CPUs) decrease dramatically. Result: simple transactions become much cheaper, but complex smart contract logic (which uses expensive storage ops) sees modest savings.
| Operation | Today (Gas) | After Repricing | % Reduction |
|---|---|---|---|
| ETH Transfer (CALL) | 21,000 | 4,500 | 78.6% |
| ERC-20 Transfer | 65,000 | ~18,000 | ~72% |
| Uniswap V3 Swap | ~150,000 | ~55,000 | ~63% |
| Storage Write (SSTORE) | 20,000 | 18,000 | 10% |
Real Transaction Cost Examples
Simple ETH transfer: Today $5–10 (at 50 gwei). After Glamsterdam: ~$0.50–1.00 (at 50 gwei gas price).
ERC-20 swap: Today $15–30. After: $4–8.
Complex DeFi position: Today $50–200. After: $15–60.
Why repricing matters: It levels the playing field. Today, only deep-pocketed traders and institutions can afford frequent transactions. Glamsterdam makes Ethereum viable for small traders, frequent batch jobs, and emerging-market users.
5. 10,000 TPS: The L1 Scaling Leap
The combination of three changes enables the 10x throughput leap:
The Throughput Equation
Current L1 TPS: ~1,000 TPS = (60M gas limit) ÷ (1.8M avg gas per tx) ÷ 12 sec block time
Glamsterdam TPS: ~10,000 TPS = (200M gas limit) ÷ (240K avg gas after repricing) ÷ 12 sec block time
Key levers: 3.3x higher gas limit + 78% lower gas per tx + parallel execution = 10x throughput
How This Stacks Against Other L1s
| Blockchain | TPS | Finality | Decentralization |
|---|---|---|---|
| Ethereum Today | ~1,000 | ~13 mins | 800K+ validators |
| Ethereum (Glamsterdam) | ~10,000 | ~13 mins | 800K+ validators |
| Solana | ~65,000 | ~13 secs | ~4,000 validators |
| Sui | ~100,000+ | ~3 secs | ~500 validators |
Glamsterdam won't match Solana's peak (Solana can reach 65K TPS in ideal conditions but averaged 1.5K TPS in 2025). But 10K TPS with Ethereum's decentralization is transformative. Arbitrum and Optimism will still offer cheaper transactions (~$0.01–0.10), but Ethereum L1 becomes viable for most user transactions.
Real-World Impact
- DeFi: More frequent rebalancing, arbitrage, and liquidations. Spreads compress; slippage decreases. Protocols can run more sophisticated strategies.
- NFTs & Gaming: Minting and trading become affordable. On-chain games are no longer cost-prohibitive for casual players.
- Payments: L1 Ethereum becomes viable for payment systems. No need to bridge to L2 for every transaction.
- Compliance: Frequent state updates become economical, enabling real-time compliance reporting and auditing.
6. Timeline & Testnet Status
As of April 2026, Glamsterdam development is in its final stages. Here's the status:
Current Phase: Final Testnet
✓ Specification Complete: All major EIPs (7732, 7928, 7904, and 25+ supporting EIPs) are in Final or Review status. Ethereum Foundation has published comprehensive specs.
✓ Client Implementation: Geth, Lighthouse, Prysm, Nimbus, and other clients have implemented Glamsterdam logic. Shadow forks are running smoothly.
✓ Public Testnets: Holesky testnet (Ethereum's official testnet) is running Glamsterdam. Testing includes consensus, execution, validator performance, and edge cases.
⊙ Security Audits: Trail of Bits, Sigma Prime, and other auditors are reviewing consensus changes. Final audits expected by May 2026.
⊙ Mainnet Readiness: Ecosystem (wallet, indexer, node operator) compatibility testing is ongoing. Target: June 2026 mainnet activation (aspirational).
Potential Timeline
- April 2026: Final testnet validation; bug fixes; security audits wrap
- May 2026: All-hands testing with clients, stakers, and major node operators. Final consensus on activation slot
- June 2026 (aspiration): Mainnet activation. Likely a specific slot (e.g., Epoch 289,000)
- Post-Activation: 4-week stabilization period; watchful monitoring for consensus issues; rollout of wallet/indexer updates
Important: This is a Hard Fork
Glamsterdam requires all validators, nodes, and clients to upgrade. Non-upgraded nodes will fork off the network. Unlike soft forks, a hard fork is not backward-compatible. Historically, Ethereum has executed hard forks flawlessly (Shanghai, Capella, Dencun), but Glamsterdam's scope (consensus + execution changes) demands extra diligence.
What can delay Glamsterdam? Major bugs discovered in testing, consensus disagreements within the community, or unexpected edge cases in parallel execution. The Ethereum Foundation and All Core Devs team are committed to launch in H1 2026, but if critical issues emerge, it could slip to Q3 2026.
7. What Glamsterdam Means for You
If You're a Regular Ethereum User
Cheaper transactions. A $20 transaction today becomes $2–3. This changes the economics of DeFi, NFTs, and everyday blockchain use. Micro-transactions and frequent trades become viable. You'll likely spend less on gas annually than you do now on a single week.
Better execution quality. More competition among builders and less MEV extraction means tighter spreads, less sandwich attacks, and better prices for swaps. Your slippage on a Uniswap trade might drop from 0.5% to 0.1%.
No wallet changes needed. Your MetaMask, Ledger, or other wallet works exactly the same. The upgrade is protocol-level; it's transparent to users.
If You're a Builder or MEV Bot Operator
New business model. MEV-Boost relays become obsolete. You'll need to adapt to ePBS's commit-reveal structure. Builder profit comes from efficient block packing, not relay intermediation. MEV doesn't disappear, but extraction becomes more visible and competitive.
Parallel execution opportunities. Bots that can efficiently declare access lists and exploit parallel execution windows will outcompete those that can't. You'll need to rethink your MEV strategies around access list constraints.
If You're a Validator or Node Operator
Higher hardware requirements. Parallel execution demands more CPU cores, RAM, and SSD bandwidth. A validator today might run on a mid-range 8-core machine; Glamsterdam ideally needs 16-32 cores. Home stakers may need hardware upgrades.
Less relay dependency. ePBS means you no longer rely on MEV-Boost relays for income. Your revenue comes directly from the protocol's ePBS auction. This is a double-edged sword: you're more autonomous but also carry more execution responsibility.
If You're a Protocol or DeFi Developer
More gas budget for complex logic. Your smart contracts can do more without hitting gas limits. Sophisticated protocols (e.g., intent-based architectures, frequent state mutations) become economically viable on L1.
Access list declarations. Your smart contracts might need to declare access lists to benefit from parallel execution. Wallets and indexers will need updates to support new transaction types.
8. Risks & Open Questions
Glamsterdam is ambitious. No upgrade of this scope is risk-free. Here are the key concerns:
Technical Risks
Consensus bugs. Moving PBS into consensus is complex. A subtle bug in the commit-reveal mechanism could break block proposals or allow censorship. The Ethereum Foundation is mitigating this through extensive testing and audits, but edge cases may remain.
Parallel execution correctness. Declaring access lists correctly is non-trivial. Smart contracts with complex state mutations or external calls might declare incomplete lists, causing reverts during execution. This could break existing dApps.
Hardware strain. Validators running underpowered machines may fall behind, breaking consensus. A split between well-resourced and under-resourced validators could lead to network instability.
Economic Risks
MEV extraction under ePBS. While ePBS moves MEV from relays to builders, it doesn't eliminate MEV. Builders still extract profit, and the mechanism might create new extraction vectors (e.g., proposer-builder collusion, sophisticated MEV bundles exploiting parallel execution).
Staker centralization. Higher hardware costs may push small home stakers off the network, concentrating validation power in well-funded staking pools. This risks long-term decentralization.
Ecosystem Risks
Wallet and indexer incompatibilities. New transaction types, access lists, and consensus changes require wallet, block explorer, and indexer updates. If major tools don't upgrade in time, users could send transactions incorrectly or miss transaction confirmation.
Smart contract incompatibilities. Contracts relying on gas metering, opcode behavior, or MEV assumptions might break. The Ethereum Foundation is publishing compatibility guides, but unforeseen issues are possible.
Open Research Questions
- Can builders reliably predict profit under ePBS? If builder economics become unpredictable, block construction might centralize around a few large builders with sophisticated modeling.
- What's the optimal gas limit? 200M might be too aggressive or too conservative. It will likely require adjustment post-activation.
- How will MEV evolve under parallel execution? New sandwich attack vectors and searcher strategies will emerge. Defenders must innovate continuously.
- Will Glamsterdam lead to L1 consolidation? If L1 becomes cheap enough, will L2s lose their relevance? Or will they focus on latency (< 1 block)? This shapes the rollup ecosystem long-term.
Mitigation Strategies
The Ethereum community is taking these risks seriously:
- Extended testnet phases (vs. rushing to mainnet)
- Multi-client implementations (Geth, Lighthouse, Prysm all building independently)
- Third-party security audits (Trail of Bits, Sigma Prime, etc.)
- Detailed ecosystem compatibility guides
- Gradual rollout: If issues emerge on mainnet, the community can coordinate to delay further activation or rollback in extreme cases (though rollback is contentious)
9. FAQ
Will my existing tokens or smart contracts be affected?
No. Glamsterdam is fully backward-compatible from a user and token perspective. Your ETH, ERC-20s, and NFTs remain unchanged. Smart contracts continue to execute. You don't need to migrate or do anything. The upgrade is transparent to application logic — only the consensus and execution layer change.
Can I use Layer 2s after Glamsterdam?
Yes, absolutely. L2s will continue operating. Glamsterdam makes L1 cheaper and faster, but L2s (Arbitrum, Optimism, Base, etc.) will still offer even lower fees (sub-cent). They'll also benefit from cheaper L1 settlement costs, allowing them to pass savings to users. Think of it as raising the baseline — L2s rise with it.
Do I need to upgrade my wallet or node immediately after Glamsterdam activates?
Not immediately, but within a few weeks. Most major wallets (MetaMask, Ledger, Trezor) will push updates before or shortly after activation. If you're running a full node, you'll need to update your client (Geth, Lighthouse, etc.) to version supporting Glamsterdam. Check your provider or node software for guidance closer to activation.
Will Glamsterdam make Ethereum faster to finalize than 13 minutes?
Not in this upgrade. Glamsterdam focuses on throughput (TPS) and MEV fairness. Finality remains ~13 minutes (64 validator committees, ~2 epochs). Future upgrades (e.g., Single Slot Finality) may reduce this, but that's out of Glamsterdam's scope.
What happens to MEV-Boost and existing relay infrastructure?
MEV-Boost becomes obsolete post-Glamsterdam. ePBS replaces it entirely. Relay operators (Lido, Flashbots) will need to transition to the new builder role. Some may shut down; others may adapt as builders themselves. This is a significant shift in the MEV supply chain, but it's intentional — moving MEV resistance from off-chain infrastructure to protocol.
Can Glamsterdam be reversed or delayed if something goes wrong?
Technically, Ethereum can delay activation by postponing the activation slot. A full rollback post-activation would be extremely controversial and unprecedented — it would require community consensus and would fork the network. For this reason, the Ethereum Foundation is extremely cautious with Glamsterdam testing. If critical issues emerge, the more likely outcome is a delay, not a rollback.
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Educational disclaimer: This guide is for informational purposes only and does not constitute financial advice. Crypto involves significant risk — do your own research before making any decisions. Learn more about our team.
Educational disclaimer: This guide is for informational purposes only and does not constitute financial advice. Crypto involves significant risk — do your own research before making any decisions. Learn more about our team.