Ethereum’s next upgrade, Fusaka, goes live in November ahead of Devconnect
Ethereum’s upcoming Fusaka hard fork is slated for early November 2025, setting the stage for one of the most consequential Ethereum network upgrades in years.
Unlike Pectra, the May 2025 fork that delivered visible changes like account abstraction and higher staking limits, Fusaka operates behind the curtain. It bundles 11 Ethereum Improvement Proposals focused on scalability, node resilience and efficiency, leaving smart contracts untouched.
A devnet launched in July 2025 and a round of Ethereum testnets in September and October will stress‑test the changes before mainnet activation.
Developers aim to ship ahead of the Devconnect conference in Buenos Aires, aligning with Ethereum’s accelerated six‑month upgrade cadence and growing focus on core performance.
Did you know? Fusaka joins a lineage of about a dozen execution‑layer hard forks (from Frontier in 2015 through Pectra in 2025).
Ethereum’s Fusaka hard fork explained
So, what is the Fusaka hard fork? It’s the next Ethereum development milestone, landing only six months after Pectra.
As part of the chain’s 2025 roadmap, Fusaka emphasizes Ethereum scalability updates and node health rather than user-facing features.
The timeline is tight: Devnet‑3 went live in July 2025, public Ethereum testnets follow in September and the mainnet fork is set for Nov. 5, 2025, coordinated to hit a predefined block height.
The choice of date is strategic, aligning with Ethereum community updates around Devconnect. By focusing on protocol refinement, this crypto hard fork lays the groundwork for future proposals like block‑time reduction while maintaining Ethereum’s reputation for steady, iterative progress.
Upcoming Ethereum network upgrades
The Ethereum Fusaka upgrade is about tuning Ethereum’s core engine. The November 2025 Ethereum hard fork bundles 11 infrastructure-level EIPs that refine scalability, improve efficiency and harden the network without breaking existing contracts.
Here’s a breakdown of what’s shipping:
- EIP‑7594 – PeerDAS: A major step in Ethereum scalability updates, this introduces peer data availability sampling so nodes don’t need to download full data blobs, lightening the load and boosting rollup performance.
- EIP‑7825 – Spam Resistance Checks: Often cited in Ethereum news as the headline item, this EIP prevents malicious transaction spam, helping nodes stay stable under high demand.
- EIP‑7823 – MODEXP Parameter Limit: Caps modular exponentiation input sizes, strengthening Ethereum’s resilience to denial‑of‑service attacks.
- EIP‑7883 – MODEXP Gas Cost Adjustment: Adjusts gas pricing for heavy cryptographic operations, an important Ethereum efficiency improvement.
- EIP‑7892 – Blob Parameter‑Only Forks: Creates a framework for lightweight blob‑related tweaks in future forks, aligning with the Ethereum 2025 roadmap.
- EIP‑7917 – Deterministic Proposer Lookahead: Precomputes block proposers to streamline validation, useful for rollups and staking operations, and noted in many ETH staking updates.
- EIP‑7918 – Blob Base Fee Bound: Links blob fees to execution costs for fairer, more predictable pricing.
- EIP‑7934 – RLP Execution Block Size Limit: Puts an upper cap on encoded block sizes, limiting bloat and supporting Ethereum scalability without breaking compatibility.
- EIP‑7935 – Default Block Gas Limit: Lays out the Ethereum gas limit increase 2025, starting around 45 million and scaling toward 150 million units, enabling more transactions per block.
- EIP‑7939 – CLZ Opcode: Adds a “count leading zeros” instruction, useful for cryptography, compression and bit‑level optimizations.
- EIP‑7951 – secp256r1 Precompile: Brings native support for the P‑256 elliptic curve, bridging Ethereum closer to Web2 security standards and wallets.
By pulling heavier proposals like EIP‑7907 and the EVM Object Format from this fork, developers kept Fusaka focused and testable.
The result is set to be a stable crypto hard fork that delivers critical back-end upgrades without disrupting DApps, exactly the kind of incremental refinement Vitalik Buterin Ethereum is known for.
Ethereum 2025 roadmap
The path to Fusaka’s activation is aggressive but deliberate, reflecting Ethereum’s new semiannual rhythm of upcoming Ethereum network upgrades.
Devnet‑3 spun up on July 23, 2025, giving developers a contained space to hammer on EIPs and stress‑test scalability tweaks. After that, attention shifted to September’s two public Ethereum testnets, short, intense cycles where client teams, node operators and DApp developers can uncover bugs before they hit mainnet.
A firm EIP freeze on Aug. 1 locked the scope, allowing roughly six weeks for interoperability checks, bug bounties and release polishing. Mainnet activation is slated for Nov. 5-12, pinned to a block height that lands just before Devconnect.
Here, it can be noted how the Ethereum 2025 roadmap blends discipline with ambition (each blockchain upgrade gets tested, fixed and launched on schedule, while developers quietly prepare the next wave).
Did you know? Ethereum’s theoretical TPS ceiling is still modest. Based on current settings (≈ 36 M gas limit, 12s block time), the maximum throughput tops out at around 142 transactions per second, well below payment networks like Visa. Fusaka’s tweaks to gas limits and block-time proposals could help push that higher.
Ethereum block time reduction proposal and gas limit increases in 2025
Fusaka is partly a response to Ethereum community updates and conference deadlines.
With Devconnect Buenos Aires on the horizon (Nov. 17-22, 2025), core contributors have been blunt about the pressure to ship.
As protocol‑support member Nixo warned,
“If we want to ship by Devconnect, we need our timeline TIGHT.”
Even as Fusaka nears release, attention is shifting toward Ethereum development for 2026’s Glamsterdam fork. That upgrade could bring bold changes like an Ethereum block time reduction proposal (EIP‑7782) to six seconds, effectively doubling throughput and making the network feel snappier for wallets and layer 2s.
Other conversations involve further gas‑limit adjustments, ETH staking updates and support for the expanding DeFi load. Decisions will crystallize at the Aug. 1 AllCoreDevs – Execution meeting, proving that Ethereum’s culture of continuous, transparent evolution is very much alive.
Ethereum testnets September 2025: What users and developers should know
For developers, Fusaka is a quiet powerhouse. Higher gas ceilings (with an initial move toward 45 million and scaling up) translate to more transactions per block, while PeerDAS relieves node workloads and improves rollup performance.
Crucially, none of these Ethereum scalability updates break contracts or interfaces; DApps and clients remain fully compatible, an important reassurance for builders.
For everyday users, the Ethereum efficiency improvements won’t scream for attention, but they’ll notice steadier gas fees and smoother transaction flow during high‑traffic moments.
Yet trade‑offs lurk; a bigger gas limit raises storage and bandwidth demands, which could strain smaller validators and nudge the network toward heavier reliance on industrial‑scale operators.
Still, Fusaka’s measured approach (refining the plumbing without overhauling the house) embodies the ethos of Vitalik Buterin’s Ethereum: Iterate, improve and make space for the next leap, all while balancing performance with decentralization.