Nomic Foundation launches slang-solx compiler with 5x speed gains for Ethereum
In brief
- Nomic Foundation launches slang-solx LLVM-based Solidity compiler with 5x faster via-IR compilation speeds.
- Solidity 0.8.37 released with low-to-medium severity bug fixes and SLOTNUM opcode support for Amsterdam upgrade.
- Slang-solx supports Solidity 0.8.34, positioned for development use rather than production deployment.
Faster compilation, clearer roadmap
Slang-solx leverages LLVM, the compiler infrastructure that powers Clang for C/C++ and Rust. This architectural choice lets developers compile smart contracts faster without rewriting the Solidity language itself. The project traces back to a compiler effort called solx that Matter Labs initiated in 2025, which later transitioned to the Nomic Foundation.
The 5x speed improvement in via-IR mode carries particular weight because via-IR is the compilation pipeline the Solidity team has been promoting as the future-facing approach to replace the older legacy pipeline. For developers working on complex contracts, this translates to faster iteration cycles and shorter feedback loops during development.
Slang-solx currently supports Solidity 0.8.34 and is explicitly positioned for development use rather than production. The Nomic Foundation has signaled a deliberate, staged rollout—developers can test the compiler now, but production deployments remain on the traditional toolchain until stability and feature parity are confirmed.
Version 0.8.37 rounds out the security push
The Solidity core team released version 0.8.35 in April 2026, version 0.8.36 in July 2026, and version 0.8.37 in September 2026, maintaining a steady cadence of updates. This latest release includes two bug fixes rated at low to medium severity.
Version 0.8.37 also introduces support for the SLOTNUM opcode tied to the Amsterdam EVM version. SLOTNUM gives contracts access to slot number information, enabling more efficient memory and storage operations. The combination of slang-solx and Solidity v0.8.37 signals something about Ethereum's broader tooling ecosystem: the core team handles language-level improvements and security patches while independent organizations like Nomic tackle performance and developer experience.
Frequently asked questions
What is slang-solx and how much faster is it?
Slang-solx is an LLVM-based Solidity compiler backend launched by the Nomic Foundation on September 7, 2026. It achieves compilation speeds up to 5x faster than the traditional solc compiler in via-IR mode and approximately 1.7x faster in legacy mode. Currently it supports Solidity 0.8.34 and is positioned for development use, not production.
What's the difference between via-IR and legacy mode?
Via-IR is the compilation pipeline the Solidity team has been promoting as the future-facing approach to replace the older legacy pipeline. Slang-solx delivers the largest speed gains in via-IR mode (5x), where the core team expects most developers to migrate over time.
What does the SLOTNUM opcode do?
SLOTNUM is a new opcode introduced in Solidity 0.8.37, tied to the Amsterdam EVM version. It gives contracts access to slot number information, enabling more efficient memory and storage operations.
