Ethereum Devs Set December Date for Fusaka Upgrade - Decrypt

This article by Decrypt covers Ethereum developers' decision to accelerate the Fusaka upgrade timeline, moving the mainnet activation from 2026 to December 3, 2025. The upgrade aims to increase blob capacity for rollups in two phases, helping reduce transaction costs on the Ethereum network. Despite encountering software bugs during recent testing that cut short evaluation periods, developers remain committed to the faster deployment schedule.

• Mainnet activation scheduled for December 3, 2025, with testnets beginning in October
• Blob capacity will increase in two phases: first to 10/15 blobs per block, then to 14/21 blobs
• Testing revealed bugs in the Prysm validator client and ckzg library, which have been addressed
• Additional testing through Devnet-6 will verify capacity numbers before public deployment