Ethereum’s Fusaka update sets the stage for a $1 trillion Layer 2 sector within six years

The Fusaka upgrade for Ethereum, aimed at boosting both scalability and node performance, is scheduled to go live on the mainnet on December 3, 2025, after a planned rollout across testnets beginning October 1, 2025, starting with the Holesky network title1 [ 1 ]. This update will include around 11-12

Improvement Proposals (EIPs), primarily concentrating on backend protocol upgrades rather than changes users directly interact with. Notably, the phased introduction of greater blob capacity through Blob Parameter Only (BPO) forks will gradually raise blob limits from 6/9 to 14/21 target/max within two weeks following the mainnet activation title1 [ 1 ]. The purpose of this increase is to substantially improve data availability for Layer 2 rollups, while lessening the bandwidth and storage requirements for node operators title2 [ 2 ].

With Fusaka, the focus is on core infrastructure, such as introducing Peer Data Availability Sampling (PeerDAS) via EIP-7594. This method lets validator nodes confirm data by examining only small samples of blobs rather than accessing the full dataset, improving scalability and keeping the network secure title1 [ 1 ]. Additionally, the block gas limit will rise from 30 million to 150 million units, marking a theoretical throughput increase of 400%, with further plans under consideration to reach 2,000 transactions per second over the next two years title2 [ 2 ]. Such upgrades are intended to keep pace with increasing transaction demand while maintaining decentralization.

Prior to the mainnet launch, a structured four-stage testnet deployment will take place. The Holesky, Sepolia, and Hoodi testnets are set to activate on October 1, October 14, and October 28, 2025, respectively, each running the complete BPO fork sequence to test the blob capacity scaling process title1 [ 1 ]. The initial BPO fork, which sets a 10/15 blob limit, is planned for December 17, 2025, with a subsequent fork on January 7, 2026, to achieve the final 14/21 limit title1 [ 1 ]. This streamlined approach enables adaptable scaling without the need for network-wide upgrades.

To strengthen security, a four-week audit competition will be held, offering up to $2 million in rewards to those who discover major vulnerabilities title2 [ 2 ]. Node operators will have staggered upgrade deadlines from September 25, 2025 (Holesky) to November 3, 2025 (mainnet), providing ample preparation time and helping to minimize interruptions title1 [ 1 ]. The Ethereum Foundation emphasizes that these precautions are vital to maintaining network robustness against bottlenecks and potential attacks.

This upgrade comes as demand grows for improvements to Ethereum’s base layer, especially in response to concerns about fragmentation among Layer 2 solutions. By increasing blob capacity and making data validation more efficient, Fusaka aims to enable more transactions without undermining decentralization title2 [ 2 ]. Industry observers point out that these steps align with expanding institutional interest in Ethereum’s core infrastructure, with some forecasting that Layer 2 networks could reach a $1 trillion market value within six years title1 [ 1 ].

The Fusaka upgrade will also introduce capped base fees for blob transactions using EIP-7918, making costs more predictable for data-intensive applications title1 [ 1 ]. More complex changes, such as the EVM Object Format (EOF) redesign, will be postponed to the next major update, Glamsterdam, in 2026, to keep the current rollout focused on crucial infrastructure upgrades title2 [ 2 ].

By rolling out phased blob scaling and PeerDAS, the upgrade is expected to lower entry barriers for smaller node operators, potentially promoting greater decentralization title1 [ 1 ]. When combined with increased gas limits, these enhancements aim to prepare Ethereum for higher transaction volumes while maintaining strong security. If successful, the upgrade could help bridge the gaps across currently fragmented multichain systems, as reflected by projects like the Open Intents Framework, which seeks to solve cross-chain interoperability issues title1 [ 1 ].