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

Claude Opus 4.8 had 44% fewer counted bugs per line than Claude Opus 5 (0.88 vs 1.58). Claude Opus 4.8 ranks #2 of 7 and Claude Opus 5 #6.

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

Claude Opus 5, with 38.3% 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 44% fewer counted bugs per line than Claude Opus 5 (0.88 vs 1.58).

Claude Opus 4.8 and Claude Opus 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 Opus 5
Relative bug rate	0.88	1.58
Rank	#2 of 7	#6 of 7
By coding agent
Claude Code	0.86	1.58
Cursor(statistically tied)	1.13	1.16
Details
Share of AI-written code, week of Sep 14	1.9%	38.3%

1.00 = average · lower is better · = statistically tied

Which has fewer bugs, Claude Opus 4.8 or Claude Opus 5?: Claude Opus 4.8 had 44% fewer counted bugs per line than Claude Opus 5 (0.88 vs 1.58). Claude Opus 4.8 ranks #2 of 7 and Claude Opus 5 #6.
Which is used more, Claude Opus 4.8 or Claude Opus 5?: Claude Opus 5, with 38.3% of the AI-written code reviewed by cubic in the week of Sep 14, 2026, against 1.9% for Claude Opus 4.8.