Why Vitalik Buterin Says Ethereum Dropped eWASM

• Ethereum dropped eWASM after Merge delays and shifting priorities stalled execution layer upgrades and reduced momentum.

• SNARK and zkEVM breakthroughs reshaped Ethereum’s VM needs, favoring proof-friendly designs over WebAssembly.

• RISC-V gained favor due to strong zkVM adoption, better SNARK compatibility, and growing tooling across ecosystems.

Vitalik Buterin revealed why Ethereum abandoned eWASM during a fireside chat at Pragma Taipei in April 2025. Speaking in Taipei, the Ethereum co-founder explained how technical delays and research breakthroughs reshaped Ethereum’s virtual machine plans. He detailed why RISC-V now fits Ethereum’s roadmap better than eWASM.

eWASM’s Early Promise and Technical Friction

Buterin said Ethereum once viewed eWASM as a replacement for the Ethereum Virtual Machine. He described the EVM as flawed, citing inefficient 256-bit design choices and problematic gas mechanics. He added that EVM architecture limited compatibility with non-crypto software.

Notably, eWASM gained appeal because browsers adopted WebAssembly. Ethereum developers expected shared tooling benefits across industries. However, progress slowed as Ethereum focused on proof-of-stake development.

Buterin explained that “The Merge” consumed development resources. As a result, Ethereum delayed large execution layer changes. He noted that eWASM might have launched around 2020 if earlier upgrades finished faster.

However, that timeline never materialized. As Ethereum priorities shifted, eWASM lost momentum. That pause opened space for alternative approaches.

SNARKs Change Ethereum’s Direction

Around 2022 and 2023, Buterin said new technologies changed Ethereum’s thinking. He pointed to SNARK systems and projects like RISC Zero. These tools emphasized zero-knowledge proof efficiency.

Buterin explained that replacing the VM required SNARK compatibility. He said Ethereum should design around proof systems from the start. That requirement reduced eWASM’s appeal.

Notably, eWASM lacked native alignment with SNARK-based execution. Meanwhile, zkEVM research accelerated across the ecosystem. Developers increasingly built systems with zero-knowledge proofs in mind.

According to Buterin, that shift forced Ethereum to reconsider its VM strategy. He stressed that a full replacement needed long-term cryptographic compatibility.

Why RISC-V Fits Ethereum’s New Path

Buterin said RISC-V gained traction across zero-knowledge virtual machines. Many zkEVM implementations now use RISC-V-based designs. He described growing adoption in open hardware projects.

Moreover, Buterin said RISC-V benefits from standardization momentum. Tooling continues expanding across crypto and traditional engineering communities. That alignment matters for Ethereum’s future execution environment.

He explained that if Ethereum commits to a VM overhaul, RISC-V offers clearer benefits. It supports SNARK-friendly execution and broader ecosystem compatibility. As a result, Ethereum shifted focus away from eWASM toward RISC-V.