Which has fewer bugs, Claude Opus 4.8 or Claude Sonnet 5?

Claude Opus 4.8 had 58% fewer counted bugs per line than Claude Sonnet 5 (0.88 vs 2.10). Claude Opus 4.8 ranks #2 of 7 and Claude Sonnet 5 #7.

Which is used more, Claude Opus 4.8 or Claude Sonnet 5?

Claude Sonnet 5, with 4.0% of the AI-written code reviewed by cubic in the week of Sep 14, 2026, against 1.9% for Claude Opus 4.8.

Updated Sep 26, 2026

Claude Opus 4.8 had 58% fewer counted bugs per line than Claude Sonnet 5 (0.88 vs 2.10).

Claude Opus 4.8 and Claude Sonnet 5 compared on relative bug rate, by coding agent, bug type, and language, and on price and usage.
Bug rate
	Claude Opus 4.8	Claude Sonnet 5
Relative bug rate	0.88	2.10
Rank	#2 of 7	#7 of 7
By coding agent
Claude Code	0.86	2.12
Details
Share of AI-written code, week of Sep 14	1.9%	4.0%

1.00 = average · lower is better

Which has fewer bugs, Claude Opus 4.8 or Claude Sonnet 5?: Claude Opus 4.8 had 58% fewer counted bugs per line than Claude Sonnet 5 (0.88 vs 2.10). Claude Opus 4.8 ranks #2 of 7 and Claude Sonnet 5 #7.
Which is used more, Claude Opus 4.8 or Claude Sonnet 5?: Claude Sonnet 5, with 4.0% of the AI-written code reviewed by cubic in the week of Sep 14, 2026, against 1.9% for Claude Opus 4.8.