Fusaka Mainnet Announcement

Fusaka is Ethereum's upgrade following Pectra, scheduled to activate on mainnet at slot 13,164,544 (December 3, 2025, 21:49:11 UTC) and described as a major step in the scaling roadmap. Its headline feature is PeerDAS, which lets nodes verify blob data availability through sampling rather than downloading entire blobs. The upgrade also plans two Blob Parameter Only forks on December 9, 2025 and January 7, 2026, raising the per-block blob target and maximum to 10 and 15 in BPO1, then 14 and 21 in BPO2. Users and exchanges generally need take no action, while node operators must update their execution and consensus clients.