Which AI model writes the most bugs in JavaScript?

As of Nov 14, 2026, Claude Sonnet 5.5 had the highest relative bug rate in JavaScript code (2.43, 143% more counted bugs than the JavaScript average).

Updated Nov 14, 2026

Best AI model for JavaScript code

As of Nov 14, 2026, GPT-6.1 Sol had the lowest relative bug rate in JavaScript code (0.52, 48% fewer counted bugs than the JavaScript average), statistically tied with GPT-6 Luna, among 6 ranked models.

Models ranked by relative bug rate in JavaScript code. Lower values are better.
Rank	Model	Rate
1= (statistically tied)	GPT-6.1 Sol	0.52
2= (statistically tied)	GPT-6 Luna	0.81
3= (statistically tied)	Claude Fable 5.1	1.16
4= (statistically tied)	Claude Opus 5.5	1.24
5= (statistically tied)	GPT-6 Astra	1.53
6	Claude Sonnet 5.5	2.43

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

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Questions and answers

Which AI model writes the most bugs in JavaScript?: As of Nov 14, 2026, Claude Sonnet 5.5 had the highest relative bug rate in JavaScript code (2.43, 143% more counted bugs than the JavaScript average).