What Is the BNB Chain Osaka/Mendel Upgrade?

The $BNB ChainOsaka/Mendel upgrade is a hard fork activated on April 28, 2026 at 02:30 UTC that bundles nine BEP proposals into a single network update, shifting focus from raw block speed to execution consistency, stable finality, and better developer tooling.

The Road That Led Here

$BNB Chain has spent the past year aggressively cutting block times. Each hard fork moved the needle:

Lorentz cut the block interval from roughly 3 seconds to 1.5 seconds

Maxwell stabilized performance around 0.75 seconds

Fermi pushed block times down to approximately 0.45 seconds

Osaka/Mendel does not chase another speed record. Instead, it tightens how the network behaves once blocks are already arriving in under a second.

What Exactly Does Osaka/Mendel Change?

The upgrade combines six adopted Ethereum EIPs with two $BNB Chain-specific improvements, each chosen for practical impact rather than alignment for its own sake.

Here is what each category delivers in practice.

Execution and Gas Improvements

Several changes address how computation runs on-chain. The upgrade introduces upper bounds on heavy operations such as modular exponentiation, adds caps on transaction gas limits, and adjusts gas costs to better reflect actual usage patterns.

A new opcode, CLZ, is also introduced. It counts leading zeros in a value and gives developers a more efficient tool at the execution layer, though most users will never interact with it directly.

Block Stability Under Load

A clear cap on block size is now enforced. This prevents individual blocks from growing heavy enough to slow processing, which matters more as daily activity increases. $BNB Chain averaged 4.5 million daily active users in Q1 2026, leading every Layer 1 network, and total value locked currently sits at $5.46 billion.

Cryptography Compatibility

Gas costs for secp256r1 cryptographic operations are updated. This standard is common in hardware security modules and mobile environments, so the adjustment makes it cheaper and more practical for developers building systems that use cryptographic standards outside the typical Ethereum stack.

The Two $BNB Chain-Specific Upgrades

These are the changes built around how $BNB Chain actually operates, not borrowed from Ethereum.

Blob transaction limits by block number. Large>What Node Operators Need to Do

Node operators must upgrade to BSC v1.7.2 before the fork goes live. Nodes running older versions risk falling out of sync with the network once Osaka/Mendel activates.

Conclusion

Osaka/Mendel is a precision upgrade. It does not change how developers build on $BNB Chain or how users interact with applications. What it does is tighten execution behavior, reduce edge-case failures during high activity, and make finality more reliable. With nine BEPs rolled into one fork, it consolidates several layers of improvement into a single, clean activation.

$BNB Chain on X: Posts (April, 2026)

Blog article by $BNB Chain: Osaka/Mendel Hard Fork: Strengthening $BNB Chain After Sub-Second Speed Gains

$BNB Chain Github: About v1.6.2