Which AI model writes the most bugs in Ruby?

As of Nov 14, 2026, GPT-6 Astra had the highest relative bug rate in Ruby code (1.25, 25% more counted bugs than the Ruby average), statistically tied with Claude Opus 5.5.

Updated Nov 14, 2026

Best AI model for Ruby code

As of Nov 14, 2026, Claude Fable 5.1 had the lowest relative bug rate in Ruby code (0.41, 59% fewer counted bugs than the Ruby average), among 3 ranked models.

Models ranked by relative bug rate in Ruby code. Lower values are better.
Rank	Model	Rate
1	Claude Fable 5.1	0.41
2= (statistically tied)	Claude Opus 5.5	0.98
3= (statistically tied)	GPT-6 Astra	1.25

1.00 = Ruby average · lower is better · = statistically tied

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Questions and answers

Which AI model writes the most bugs in Ruby?: As of Nov 14, 2026, GPT-6 Astra had the highest relative bug rate in Ruby code (1.25, 25% more counted bugs than the Ruby average), statistically tied with Claude Opus 5.5.