Ethereum Upgrade: Fusaka Set to Launch on December 3, 2025 – What You Need to Know

• What Is the Fusaka Upgrade and Why Does It Matter?
• When Will Fusaka Go Live?
• Key Features of Fusaka
• Security First: The $2 Million Audit
• What’s Next After Fusaka?
• How to Prepare as an Investor or Developer?
• Frequently Asked Questions

The ethereum network is gearing up for its next major upgrade, Fusaka, scheduled to go live on December 3, 2025. This update aims to enhance scalability, security, and decentralization, with key features like increased blob capacity, PeerDAS, and higher gas limits. Testnets will roll out in October, and a $2 million audit is underway to ensure a smooth transition. Here’s a deep dive into what Fusaka brings to the table and why it matters for Ethereum users and developers.

What Is the Fusaka Upgrade and Why Does It Matter?

The Fusaka upgrade is Ethereum’s next big leap, following Pectra (May 2025) and Dencun (March 2024). Named after a Japanese mountain, Fusaka focuses on scalability without compromising decentralization. In my experience covering Ethereum upgrades, this one stands out for its phased approach to increasing blob capacity—a critical feature for rollups. Christine Kim, a noted Ethereum researcher, puts it bluntly: "Fusaka’s blob capacity could more than double post-launch, based on Devnet-5 tests."

When Will Fusaka Go Live?

Mark your calendars: Fusaka’s mainnet launch is set for. But before that, testnets will get a trial run:

• Holesky: October 1, 2025
• Sepolia: October 14, 2025
• Hoodi: October 28, 2025

Key Features of Fusaka

Fusaka isn’t just another update; it’s a game-changer. Here’s what’s under the hood:

• Blob Capacity Boost: Starting December 17, 2025, blobs per block jump from 6–9 to 10–15. By January 7, 2026, that climbs to 14–21. (Source: Devnet-5 tests)
• PeerDAS: Validators can now sample tiny bits of data from peers instead of downloading entire blobs—saving time and bandwidth.
• Gas Limit Hike: From 30 million to 150 million units per block, slashing Layer 2 rollup costs. Optimism’s analysis suggests Ethereum could handle 3,500 user ops/sec, up from 220.

Security First: The $2 Million Audit

Safety isn’t an afterthought. On September 15, 2025, the Ethereum Foundation launched aon Sherlock, with Gnosis and Lido chipping in $100K and $25K respectively. Flaw hunters get double rewards Week 1, plus 50% extra Week 2. Talk about incentives!

What’s Next After Fusaka?

Ethereum’s roadmap doesn’t stop here., slated for 2026, promises faster blocks. But let’s not get ahead of ourselves—Fusaka’s the star for now.

How to Prepare as an Investor or Developer?

For devs: Test your dApps on Holesky/Sepolia. For traders? Watch gas fees—they’ll likely dip post-upgrade. And hey, if you’re swapping ETH, platforms like BTCC offer low fees (just saying).

Data sources: CoinMarketCap, TradingView.