---
title: "Should I write a circuit by hand or use a zkVM?"
description: "Hand-written circuits give the smallest proving cost and the tightest control, at the price of specialist engineering and a large underconstrained-bug…"
type: "question"
url: "https://zkpick.com/faq/should-i-write-a-circuit-by-hand-or-use-a-zkvm/"
section: "02 Choosing a framework"
authors:
  - "MarketComp"
publisher: "MarketComp"
version: "1.3"
updated: "2026-09-12"
license: "CC-BY-4.0"
json: "https://zkpick.com/data/faq/should-i-write-a-circuit-by-hand-or-use-a-zkvm.json"
---

*By MarketComp. Updated 2026-09-12. Version 1.3. CC BY 4.0.*

# Should I write a circuit by hand or use a zkVM?

Hand-written circuits give the smallest proving cost and the tightest control, at the price of specialist engineering and a large underconstrained-bug surface that only circuit-literate reviewers can assess. A zkVM lets you prove ordinary programs, shrinking the code your team must get right and shifting much of the soundness burden onto the zkVM's own audited implementation — but proving costs are typically orders of magnitude higher, and you inherit the zkVM's trust assumptions and bugs. Choose the zkVM when engineering time and correctness risk dominate; choose the hand-written circuit when proving cost dominates and the statement is small and stable. See Section 02.