Today, Linea and Ethereum Mainnet upgrade simultaneously for the first time. In 2025 alone, four Ethereum hard forks from Paris through Prague were delivered to get Linea up to speed. Now we’re showing that zkEVMs can keep pace with Ethereum's upgrade cadence, something many thought impossible.

The timeline shows the story of our evolution:

• zkEVM to London: 4 years

• London to Prague: 4 months

• Prague to Osaka: real-time 

The challenge and why it matters

Most zkVM teams take a RISC-V approach: they run an Ethereum client inside a RISC-V virtual machine, which means they don't need to rewrite ZK proofs for each fork. We believe the trade-off is this sacrifices efficiency and performance.

Linea chose a different path. We develop ZK proofs directly for the EVM, which gives us superior efficiency and performance. This requires manual work for every single fork. Most teams gave up on this approach, convinced it was too difficult to maintain.

With Osaka, we take another step in demonstrating it can actually be viable at scale.

How we did it

Over the past four years, we have created most of Linea’s EVM arithmetization modules manually. This hard work laid the foundation we can now build upon to deliver upcoming upgrades much faster, as demonstrated with Fusaka. In parallel, we also implemented  zkASM, a high-level "source language" that generalizes EVM constraint logic and compiles directly into circuits. zkASM will allow us to implement any ZK circuits much faster. 

What this means for Linea users

For Linea users and dapps, this milestone means one thing: no waiting. When Ethereum upgrades, you get the newest EVM features immediately. 

With Osaka support live, developers can deploy the latest Solidity codebases and leverage cutting-edge EVM features without modification. For example:

• EIP-7951 enables native Passkey support via secp256r1, letting users sign with FaceID/TouchID while significantly lowering signature-verification costs for developers.

• Efficiency improvements like EIP-7939 and zkEVM-friendly updates streamline execution, while increased blob capacity and refined fee mechanisms reduce rollup data availability costs and improve scalability. 

Together, these changes enhance onboarding, security, and overall performance on Linea.