BNB Chain to activate Pasteur hard fork on August 25 with throughput upgrades

Key features of the Pasteur hard fork

According to the BNB Chain development team, the Pasteur upgrade will focus on several new functionalities beyond network speed. Notably, the hard fork brings improvements in bridge verification, validator key management, and block capacity, aiming to bolster security and scalability on BSC.

The upgrade encompasses three main proposals, grouped under BEP-673. These changes are: stronger bridge verification protocols (BEP-682), secure retirement of validator keys (BEP-695), and the introduction of fuller transaction blocks at existing speeds (BEP-675).

Developers have underscored that the recent hard forks, Fermi and Osaka/Mendel, prioritized increasing transaction speeds, reducing block times to 0.45 seconds. The Pasteur upgrade builds on this foundation, redirecting efforts toward more efficient use of network speed and addressing validator governance issues.

BEP-682 and BEP-695 directly enhance the chain’s security and layer improvements for bridge, staking, and governance procedures.

BEP-675, meanwhile, introduces the ability for block builders to submit pre-executed blocks, which validators check against consensus rules before signing and broadcasting. This mechanism is designed to fill blocks more completely, enhancing transaction throughput without compromising network integrity.

On testnet benchmarks, BEP-675 increased transaction processing from 1,237 to 2,324 transactions per second (TPS).

Pasteur is about harnessing increased speed for efficient throughput, introducing stronger bridge verification and safer validator key retirement, while also enabling more transactions per block at the same speed.

Activation schedule and upgrade instructions

The Pasteur hard fork has been operating on the BSC testnet since July 21, 2026. The mainnet activation is officially set for August 25, 2026, at 02:30 AM UTC. BNB Chain has advised node operators to update their systems to version 1.7.7 before this deadline to ensure a smooth transition.

BNB Chain is an open-source, decentralized blockchain platform specializing in fast, low-cost transactions, and supports applications across DeFi, NFTs, and web3 infrastructure.

The planned upgrade is designed to address both network security and operational efficiency as part of BNB Chain’s ongoing strategy to scale throughput and stabilize ecosystem growth.

Path to future scaling

Throughout the first half of 2026, BSC implemented several key scalability measures, such as reducing block intervals to 450 milliseconds and lowering in-memory finality to 650 ms. These optimizations nearly doubled benchmark throughput, which now approaches 5,200 TPS.

The Pasteur hard fork marks the start of BNB Chain’s second-half 2026 roadmap, with the stated goal of again doubling mainnet throughput and driving progress toward a tenfold overall increase in transaction capacity.

The “capacity workstream” supported by BEP-675 is central to this objective, aiming to maximize the use of available block space and improve the handling of high transaction volumes.

Developers have indicated that these enhancements fit within a broader effort to ensure BNB Chain remains competitive in handling large, demanding decentralized applications.

Mini dictionary: BEP (BNB Evolution Proposal), a technical standard used for proposing improvements and changes to the BNB Chain protocol. BEPs outline upgrades ranging from governance rules to consensus mechanisms and network infrastructure.