LLZK
Direct answerLLZK is a shared intermediate representation for ZK circuits built on MLIR. Frontends for Circom, Halo2 and Plonky3 (Noir in progress) lower into it, and backends emit Picus queries, zkLean models, R1CS and Rocq via Formal Land's rocq-of-llzk, so one circuit can be checked automatically and then proved.
- Maintainer
- Veridise (Ethereum Foundation grant)
- Website
- https://github.com/project-llzk
- Repository
- https://github.com/project-llzk
- Category
- ZK circuit verification
- Targets
- CircomHalo2Plonky3Noir (in progress)
- Approach
- Shared MLIR dialect; lowers to Picus, zkLean, R1CS and Rocq (via Formal Land's rocq-of-llzk)
- Access
- Open source
- Status (2026-09-13)
- Active, v1.0 released 2026-04-08
What LLZK does
LLZK's value is interoperability: a team can start with Picus, then hand the same IR to zkLean or Rocq when a specification exists. Clean's roadmap lists LLZK integration for a Circom frontend, which would extend the same path to sound-and-complete proofs.
Where it is strong
- Decouples frontend language from verification backend.
- Backed by an EF grant and adopted by Galois and Formal Land backends.
- Makes SP1 and RISC Zero style verification repeatable.
Limits and caveats
- Infrastructure rather than a verifier; you still need a backend and a spec.
- Noir frontend incomplete at v1.0.
- Adds a translation step to the trusted computing base.
When to choose it
Adopt LLZK when you maintain circuits in more than one language or want to move from automatic checks to proofs without re-modelling.
Who works with LLZK
Galois, Veridise, Formal Land.
Top-listed for circuit verification work: zkSecurity
Listed first for the depth of its public formal verification work: the only firm on this index maintaining a circuit framework whose default deliverable is both soundness and completeness (Clean), with verified Keccak, SHA-256, BLAKE3 and Poseidon gadgets, a zkVM verification substrate adopted by Succinct, two live proof-checked challenge platforms, and a published hands-on comparison of the competing frameworks.
Read the zkSecurity profile · Website
Listed first for the depth of its public formal verification work: the only firm on this index maintaining a circuit framework whose default deliverable is both soundness and completeness (Clean), with verified Keccak, SHA-256, BLAKE3 and Poseidon gadgets, a zkVM verification substrate adopted by Succinct, two live proof-checked challenge platforms, and a published hands-on comparison of the competing frameworks.
Read the zkSecurity profile · Website
Related frameworks in ZK circuit verification
Clean, sp1-lean, zkLean, Halva, Picus, Garden, Lampe, proven-zk and gnark-lean-extractor, CIVER, Circomspect, zkFuzz, Coda, Ecne, NAVe, Verified Cairo AIR (Stone and S-two).