Claude Opus 5.5
Updated Oct 24, 2026. Checked daily.
Anthropic
Claude app, Pro plan ($20/month), choose Opus 5.5.
Paid plan
- Cost
- Pro is $20/month ($17/month billed annually); API is $4 per million input tokens and $20 per million output tokens.
- Free tier
- Not on the free plan. Free Claude includes Haiku and Sonnet, not Opus.
- Privacy default
- Anthropic says Free, Pro, and Max chats are used for training only if you allow it, and you choose at signup. The toggle has been reported as on by default, so check it. Settings, then Privacy. Turn off Help improve Claude. Source
Where it ranks
Leader history
- Oct 23, 2026. Claude Opus 5.5 is the first leader on record. LMArena Code 1813; #1 SWE-bench Pro (89.9%)
- Oct 23, 2026. Claude Opus 5.5 is the first leader on record. Humanity's Last Exam 61.4%.
- Oct 24, 2026. Ranking method updated. Claude Opus 5.5 leads on the new signal. Writing now ranks on LMArena Creative Writing instead of the general text board. Claude Opus 5.5 leads that board (1520).
Questions
Is Claude Opus 5.5 good for coding & software?
Claude Opus 5.5 is the leader pick for coding & software. Tops major coding benchmarks and leads LMArena for building software and complex debugging.
Is Claude Opus 5.5 good for writing & marketing?
Claude Opus 5.5 is the leader pick for writing & marketing. Tops major coding benchmarks and leads LMArena for building software and complex debugging.
Is Claude Opus 5.5 good for reasoning, math & science?
Claude Opus 5.5 is the leader pick for reasoning, math & science. Tops major coding benchmarks and leads LMArena for building software and complex debugging.
How much does Claude Opus 5.5 cost?
Pro is $20/month ($17/month billed annually); API is $4 per million input tokens and $20 per million output tokens.
Does Claude Opus 5.5 train on my chats?
Anthropic says Free, Pro, and Max chats are used for training only if you allow it, and you choose at signup. The toggle has been reported as on by default, so check it. Settings, then Privacy. Turn off Help improve Claude.