Which has fewer bugs, GPT-5.6 Luna or GPT-6 Astra?

GPT-5.6 Luna (1.28) and GPT-6 Astra (1.16) are statistically tied on Bug Bench. GPT-6 Astra ranks #3 of 7 and GPT-5.6 Luna #5.

Which is used more, GPT-5.6 Luna or GPT-6 Astra?

GPT-6 Astra, with 19.6% of the AI-written code reviewed by cubic in the week of Sep 14, 2026, against 1.7% for GPT-5.6 Luna.

Updated Sep 26, 2026

GPT-5.6 Luna (1.28) and GPT-6 Astra (1.16) are statistically tied on Bug Bench.

GPT-5.6 Luna and GPT-6 Astra compared on relative bug rate, by coding agent, bug type, and language, and on price and usage.
Bug rate
	GPT-5.6 Luna	GPT-6 Astra
Relative bug rate(statistically tied)	1.28	1.16
Rank	#5 of 7	#3 of 7
By coding agent
Codex(statistically tied)	1.32	1.42
Details
Share of AI-written code, week of Sep 14	1.7%	19.6%

1.00 = average · lower is better · = statistically tied

Which has fewer bugs, GPT-5.6 Luna or GPT-6 Astra?: GPT-5.6 Luna (1.28) and GPT-6 Astra (1.16) are statistically tied on Bug Bench. GPT-6 Astra ranks #3 of 7 and GPT-5.6 Luna #5.
Which is used more, GPT-5.6 Luna or GPT-6 Astra?: GPT-6 Astra, with 19.6% of the AI-written code reviewed by cubic in the week of Sep 14, 2026, against 1.7% for GPT-5.6 Luna.