Base Network Upgrades
PlanningBase upgrade
Denim
Denim introduces native blocks at a 200ms cadence, millisecond-resolution RPC timestamps, and onchain millisecond time through BaseTime.- Base Sepolia: Targeting November 2026
- Base Mainnet: Targeting November 2026
PlanningBase upgrade
Cobalt
Cobalt adds native account abstraction with EIP-8130, improves the B20 token standard, and introduces dynamic node upgrades.- Base Sepolia: Targeting September 2026
- Base Mainnet: Targeting September 2026
LiveBase upgrade
Beryl
Beryl makes Base a first-class issuance platform with B20 tokens, reduces withdrawal delays, and adopts Reth V2 as the reference execution client.- Base Sepolia: Activated June 18, 2026
- Base Mainnet: Activated June 25, 2026
LiveBase upgrade
Azul
Azul is Base’s first independent network upgrade. It strengthens security and decentralization, advances the path to 1 gigagas per second, and improves the developer experience.- Base Sepolia: Activated April 20, 2026
- Base Mainnet: Activated May 28, 2026
Upstream OP Stack Hardforks
Base adopted the following upstream OP Stack hardforks. Entries are ordered by Base Mainnet activation date.LiveOP Stack
Jovian
Jovian introduces a configurable minimum base fee and a data availability footprint gas scalar for improved fee-market stability.- Base Sepolia: Activated November 19, 2025
- Base Mainnet: Activated December 2, 2025
LiveOP Stack
Isthmus
Isthmus incorporates Ethereum Pectra EIPs and introduces the operator fee mechanism for sequencer revenue.- Base Sepolia: Activated April 17, 2025
- Base Mainnet: Activated May 9, 2025
LiveOP Stack
Holocene
Holocene introduces dynamic EIP-1559 parameters configurable throughSystemConfig and stricter block derivation rules.- Base Sepolia: Activated November 26, 2024
- Base Mainnet: Activated January 9, 2025
LiveOP Stack
Granite
Granite addsbn256Pairing precompile input-size restrictions and updates the channel timeout parameter.- Base Sepolia: Activated August 12, 2024
- Base Mainnet: Activated September 11, 2024
LiveOP Stack
Fjord
Fjord introduces FastLZ-based L1 fee estimation, the RIP-7212secp256r1 precompile, and Brotli channel compression.- Base Sepolia: Activated May 29, 2024
- Base Mainnet: Activated July 10, 2024
LiveOP Stack
Ecotone
Ecotone integrates Ethereum Dencun changes, including EIP-4844 blob transactions and EIP-4788 beacon block roots.- Base Sepolia: Activated February 21, 2024
- Base Mainnet: Activated March 14, 2024
LiveOP Stack
Delta
Delta introduces span batches to reduce L1 data costs by compressing multiple L2 blocks into a single batcher transaction.- Base Sepolia: Activated December 22, 2023
- Base Mainnet: Activated February 22, 2024
LiveOP Stack
Canyon
Canyon brings Ethereum Shanghai EIPs, including EIP-3651, EIP-3855, and EIP-3860, to the Base execution layer.- Base Sepolia: Activated November 14, 2023
- Base Mainnet: Activated January 11, 2024