Miri
Hacker ApprovedRanked 2 of 6 sanitizers by recommenders
Free Rust tool that runs your tests and flags undefined behavior and memory violations in unsafe code. Critics say it has bugs and limitations and cannot catch everything.
Free Rust tool that runs your tests and flags undefined behavior and memory violations in unsafe code. Critics say it has bugs and limitations and cannot catch everything.
29 people gave an opinion
- recommend it
- 26
- criticize it
- 3
- approval share
- 90%
Recommended in 12 of 13 months
- November 2025: recommended
- December 2025: recommended
- January 2026: recommended
- February 2026: recommended
- March 2026: recommended
- April 2026: recommended
- May 2026: recommended
- June 2026: recommended
- July 2026: recommended
- August 2026: recommended
- September 2026: recommended
- October 2026: recommended
- November 2026: not recommended (month in progress)
Why it carries the badge
- 26 people recommend itNeeds 10 or more, met.
- 8.7 recommenders for every criticNeeds 2 to 1 or better, met.
- Recommended in 12 of 13 monthsNeeds 4 or more, met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Catches undefined behavior at runtime
“Unsafe Rust actually has a great runtime analyzer: Miri. It's very easy to just run cargo +nightly miri test in your project”
Comment from 2 Nov 2025 in “Notes by djb on using Fil-C” “you can also verify the unsafe implementation using Miri which is a significantly strong runtime checker”
Comment from 11 Nov 2025 in “Memory Safety for Skeptics” “run those tests under Miri, which will loudly complain if you perform any memory-unsafe operations”
Comment from 29 Apr 2026 in “Bugs Rust Won't Catch” - Comment from 11 Dec 2025 in “Rust in the kernel is no longer experimental”
- Comment from 5 Dec 2025 in “Thoughts on Go vs. Rust vs. Zig”
- Comment from 21 Mar 2026 in “We rewrote our Rust WASM Parser in TypeScript – and it got 3x Faster”
Easy to run from the command line
“Unsafe Rust actually has a great runtime analyzer: Miri. It's very easy to just run cargo +nightly miri test in your project”
Comment from 2 Nov 2025 in “Notes by djb on using Fil-C” “Rust has things like miri that can help you write your unsafe code and it's just a command line invocation away.”
Comment from 20 Jul 2026 in “Claude Code uses Bun written in Rust now” Useful for crates that use unsafe
“If you have a codebase that uses unsafe, I highly recommend running your tests through Miri”
Comment from 2 Jan 2026 in “Miri: Practical Undefined Behavior Detection for Rust [pdf]” “It is a great tool for those of us that have crates that need to use unsafe”
Comment from 2 Jan 2026 in “Miri: Practical Undefined Behavior Detection for Rust [pdf]” Stronger than sanitizers
“run `miri`, which is like a sanitizer on steroids”
Comment from 19 Feb 2026 in “Zero-day CSS: CVE-2026-2441 exists in the wild” “Miri is a stronger proof than sanitizers”
Comment from 22 Oct 2026 in “Rust Style Guide”
Other sanitizers people recommend
The four most recommended other sanitizers, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
| Product | Recommend | Criticize | Approval | Months | Owned | Badge |
|---|---|---|---|---|---|---|
| Valgrind | 29 | 8 | 78% | 13 | — | Approved |
| MiriThis page | 26 | 3 | 90% | 12 | — | Approved |
| AddressSanitizer | 21 | 4 | 84% | 7 | — | Approved |
| UndefinedBehaviorSanitizer | 12 | 0 | 100% | 5 | — | Approved |
| Go race detector | 5 | 1 | 83% | 4 | — | — |
What people said
31 of the 33 comments that mention it, newest first. Each links to the original comment.
“Miri is a stronger proof than sanitizers”
“miri and loom both have analyzers that can check some non-sequentially-consistent behavior”
“Miri stores all environment variables to target/,”
“do it unsafe there, test with miri”
“Not to mention the availability of advanced tooling like MIRI.”
“they just want to maintain their url”
“I've done this all before and it works fine.”
“Rust has things like miri that can help you write your unsafe code and it's just a command line invocation away.”
“Try Miri with the new Bun project. It's currently blowing up.”
“Miri checks aliasing violations dynamically, making it a natural complement.”
“Miri, all respect to it, has bugs, probability-based testing and other limitations and issues.”
“Rust also has Miri, and a much better baseline for static analysis.”
“Will definitely use that going forward”
“backpressure the rewrite with tools like miri”
“would have trivially uncovered this error before it made it to the mainline”
“run those tests under Miri, which will loudly complain if you perform any memory-unsafe operations”
“really solid tools like Miri for finding undefined behavior”
“This sucks because there's no way to configure it to skip over the crate”
“run `miri`, which is like a sanitizer on steroids”
“Rust with miri/cargo-deny/cargo-check/cargo-fmt”
“I almost always find I have made mistakes that Miri catches.”
“Many of them were real unsoundness bugs due to reference aliasing.”
“If you have a codebase that uses unsafe, I highly recommend running your tests through Miri”
“It is a great tool for those of us that have crates that need to use unsafe”
“You can run your pointer-fiddling code in Miri today to check that you're following the rules.”
“Miri cannot catch everything, and is magnitudes slower than regular program running.”
“There are tools like Miri that allow us to test that we haven't broken the rules.”
“you can also verify the unsafe implementation using Miri which is a significantly strong runtime checker”
“it lets us exercise safe code to ensure there aren't memory violations caused by incorrect MIR lowering”
“Unsafe Rust actually has a great runtime analyzer: Miri. It's very easy to just run cargo +nightly miri test in your project”
“use tools like Miri to make sure they upheld”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.