# CompCert 9 Hacker News commenters recommended CompCert and 2 criticized it, November 2025 to November 2026. It was recommended in 8 of 13 months. **Verdict:** Formally verified C compiler trusted for safety-critical code and fast native output. Critics report a wrong-output bug and code worse than gcc -O0. ## Why people recommend it - Proven correct compiler (5 comments): "Check out seL4 and CompCert for real-world examples of complex software proven correct and used in industry." ([source](https://news.ycombinator.com/item?id=48728244)) "the hard part of compiler correctness is already handled by the efforts of CompCert" ([source](https://news.ycombinator.com/item?id=46656987)) "a proven correct C compiler used by Airbus and others for real production software" ([source](https://news.ycombinator.com/item?id=49119257)) - Used in safety-critical industry (3 comments): "It's the actual way that companies that have large C code bases in safety-critical industries verify their code." ([source](https://news.ycombinator.com/item?id=50018016)) "a proven correct C compiler used by Airbus and others for real production software" ([source](https://news.ycombinator.com/item?id=49119257)) "a proven correct C compiler used by Airbus" ([source](https://news.ycombinator.com/item?id=49119739)) - Example of verified software (2 comments): "Check out seL4 and CompCert for real-world examples of complex software proven correct and used in industry." ([source](https://news.ycombinator.com/item?id=48728244)) "CompCert is an example of how to do this." ([source](https://news.ycombinator.com/item?id=49369421)) ## Alternatives hackers recommend - [Fil-C](https://hackerapproved.com/p/fil-c.md): 160 recommend - [Claude's C Compiler](https://hackerapproved.com/p/claude-s-c-compiler.md): 39 recommend - [Visual C++](https://hackerapproved.com/p/visual-c-plus-plus.md): 29 recommend - [Tiny C Compiler (TCC)](https://hackerapproved.com/p/tcc.md): 22 recommend - [Microsoft Visual C++ compiler (MSVC)](https://hackerapproved.com/p/msvc.md): 20 recommend ## Cite as Hacker Approved, "CompCert", https://hackerapproved.com/p/compcert/ (counts from 1,795,640 Hacker News comments, November 2025 to November 2026).