cargo-mutants by sourcefrog
Inject bugs and see if your tests catch them!
About cargo-mutants
From the project's README at github.com/sourcefrog/cargo-mutants. Lightly cleaned for readability; for the full source see the upstream repo.
[](https://github.com/sourcefrog/cargo-mutants/actions/workflows/tests.yml?query=branch%3Amain) [](https://crates.io/crates/cargo-mutants) [](https://lib.rs/crates/cargo-mutants) [](https://github.com/sponsors/sourcefrog) [](https://donate.stripe.com/fZu6oH6ry9I6epVfF7dfG00)
cargo-mutants helps you improve your program's quality by finding places where bugs could be inserted without causing any tests to fail.
Coverage measurements can be helpful, but they really tell you what code is reached by a test, and not whether the test really checks anything about the behavior of the code. Mutation tests give different information, about whether the tests really check the code's behavior.
The goal of cargo-mutants is to be easy to run on any Rust source tree, and to tell you something interesting about areas where bugs might be lurking or the tests might be insufficient.
Health score breakdown
6-dimension composite. See methodology for formula and weights.
Adoption signals
Real-world usage data, pulled from each registry. The bigger the numbers, the more battle-tested the project.
| Signal | Value | Source |
|---|---|---|
| GitHub stars | 1.1k | github.com/sourcefrog/cargo-mutants |
| GitHub forks | 38 | github.com/sourcefrog/cargo-mutants |
| CRATES downloads (last month) | 53k | cargo-mutants |
Release & maintenance
Is this project actively maintained, or about to die? Check the recency of last commit and last release.
| Project age | 4.7 years | since Sep 2021 |
| Last commit | 21 days ago | Apr 16, 2026 |
| Releases shipped | 64 | last: 2 months ago |
| Security policy | SECURITY.md | declared by maintainers |
| Funding links | 3 | declared by maintainers |
Self-hosting cost across providers
Detected requirements: 4GB RAM, 40GB disk minimum. Cheapest plan per provider that meets the requirement.
| Provider | Plan | Specs | Monthly | |
|---|---|---|---|---|
| hetzner | CAX11 | 2c · 4GB · 40GB | $4.13 USD | Deploy → |
| vultr | VC2 | 1c · 1GB · 25GB | $5 USD | Deploy → |
| linode | Nanode 1GB | 1c · 1GB · 25GB | $5.12 USD | Deploy → |
| digitalocean | Basic Regular 1GB | 1c · 1GB · 25GB | $6 USD | Deploy → |
What people say on Hacker News
Ready to self-host cargo-mutants?
Spin up a hetzner CAX11 (4GB RAM, 40GB disk) for $4.13/mo and follow the project's official install docs.
Data last refreshed May 7, 2026.
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