Which has fewer bugs, Claude Fable 5 or GPT-6 Astra?

Claude Fable 5 had 40% fewer counted bugs per line than GPT-6 Astra (0.70 vs 1.16). Claude Fable 5 ranks #2 of 9 and GPT-6 Astra #5.

Which is cheaper, Claude Fable 5 or GPT-6 Astra?

Both list at $10 input / $50 output per 1M tokens.

GPT-6 Astra, with 19.6% of the AI-written code reviewed by cubic in the week of Sep 14, 2026, against 0.9% for Claude Fable 5.

Updated Sep 26, 2026

Claude Fable 5 had 40% fewer counted bugs per line than GPT-6 Astra (0.70 vs 1.16).

Claude Fable 5 and GPT-6 Astra compared on relative bug rate, by coding agent, bug type, and language, and on price and usage.
Bug rate
	Claude Fable 5	GPT-6 Astra
Relative bug rate	0.70	1.16
Rank	#2 of 9	#5 of 9
Details
Provider	Anthropic	OpenAI
Released	Jun 9, 2026	Sep 4, 2026
List price	$10 input / $50 output per 1M tokens	$10 input / $50 output per 1M tokens
Share of AI-written code, week of Sep 14	0.9%	19.6%

1.00 = average · lower is better

Which has fewer bugs, Claude Fable 5 or GPT-6 Astra?: Claude Fable 5 had 40% fewer counted bugs per line than GPT-6 Astra (0.70 vs 1.16). Claude Fable 5 ranks #2 of 9 and GPT-6 Astra #5.
Which is cheaper, Claude Fable 5 or GPT-6 Astra?: Both list at $10 input / $50 output per 1M tokens.
Which is used more, Claude Fable 5 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 0.9% for Claude Fable 5.