Ethereum Sets December 3 for Fusaka Upgrade as Developers Complete Final Testnet Deployment

Major Network Upgrade Targets Data Efficiency, Higher Gas Limits, and Layer-2 Scalability

TL;DR:

• Ethereum’s Fusaka hard fork will go live on December 3 2025 at slot 13,164,544, following a successful Hoodi testnet deployment on October 29.
• The upgrade expands block gas limits from 30 million to 150 million and introduces Peer Data Availability Sampling (PeerDAS, EIP-7594) for more efficient validator performance.
• Around 11–12 EIPs are bundled, supported by a $2 million audit bounty, marking one of Ethereum’s most significant updates since the Merge.

Ethereum developers have confirmed that the long-anticipated Fusaka hard fork will activate on December 3 2025, establishing a pivotal milestone in the network’s multi-year “Surge” roadmap. The date was locked in following the successful rollout of Fusaka on the Hoodi testnet on October 29 at 18:53 UTC, the final step after deployments on the Holesky and Sepolia testnets earlier in October. The All Core Devs call that followed sealed the decision, with slot 13,164,544 targeted for activation at approximately 21:49 UTC.

The Fusaka upgrade focuses on improving scalability and data efficiency, setting the stage for Ethereum’s next evolutionary phase. Developers are preparing to lift the block gas limit from around 30 million units to 150 million units, dramatically expanding the network’s transaction-handling capacity. The introduction of PeerDAS (Peer Data Availability Sampling, EIP-7594) is designed to let validators sample only small portions of “blob” data rather than entire datasets, reducing storage strain and increasing node efficiency—particularly beneficial for Layer-2 rollups that rely on blob data to batch transactions. Nethermind described the testnet rollout as “another smooth upgrade, another key milestone on the road to Fusaka,” underscoring the network’s growing technical maturity.

Developers expect Fusaka to trigger a two-stage increase in blob capacity immediately after mainnet activation: from roughly 6 to 9 blobs per block initially, rising toward 14 to 21 within two weeks. Current averages stand near 5.1 blobs per block—up sharply from 0.9 in March 2023—reflecting growing demand from rollup networks. These expansions could push the network’s aggregate throughput across all layers to as high as 12,000 transactions per second by 2026, according to projections circulating among developer circles.

Security measures around the rollout are equally rigorous. The Ethereum Foundation has launched a four-week bounty program offering up to $2 million to researchers who uncover vulnerabilities before the December activation. The foundation’s approach emphasizes both caution and transparency as client teams complete final code reviews. The Fusaka release is expected to bundle roughly a dozen Ethereum Improvement Proposals, spanning data-availability improvements, validator efficiency, and transaction cost optimization.

While the technical leap is substantial, analysts caution that the Fusaka hard fork alone won’t resolve competitive pressures from alternative Layer-1 and Layer-2 ecosystems or broader macro-economic risks shaping today’s crypto price index. Ethereum’s market performance at the time of announcement reflected measured optimism: ETH traded slightly above $3,800 but briefly slipped below $3,700 as volatility across the coin market cap persisted. During that same 24-hour window, total liquidations reached $220.8 million, with $190.3 million coming from long positions — a reminder that technical progress does not always translate immediately into price stability within the crypto price landscape.

After the December deployment, Ethereum’s focus will shift toward its next major upgrade, code-named “Glamsterdam,” which aims to refine block times and advance proposer-builder separation. Together, Fusaka and its successor will form the backbone of Ethereum’s continued scaling strategy—strengthening the network’s infrastructure for both developers and users as the world’s second-largest blockchain by coin market cap continues its slow but deliberate march toward greater efficiency and accessibility.

This article has been refined and enhanced by ChatGPT.