Which AI model writes the most bugs in C#?

As of Nov 14, 2026, Claude Opus 5.5 had the highest relative bug rate in C# code (1.22, 22% more counted bugs than the C# average).

Updated Nov 14, 2026

Best AI model for C# code

As of Nov 14, 2026, GPT-6.1 Sol had the lowest relative bug rate in C# code (0.27, 73% fewer counted bugs than the C# average), among 2 ranked models.

Models ranked by relative bug rate in C# code. Lower values are better.
Rank	Model	Rate
1	GPT-6.1 Sol	0.27
2	Claude Opus 5.5	1.22

1.00 = C# average · lower is better

Other languages

TypeScript
Python
JavaScript
SQL
Go
Shell
Rust
Swift
Ruby
Vue
Terraform
PHP
Svelte
Java
Kotlin
Dart
Elixir

Questions and answers

Which AI model writes the most bugs in C#?: As of Nov 14, 2026, Claude Opus 5.5 had the highest relative bug rate in C# code (1.22, 22% more counted bugs than the C# average).