Claude
@claudeai · Sep 22, 2026
Introducing Claude Opus 5.5, the first model in our new Claude 5.5 family.
It performs at the level of Claude Fable 5.1 for most tasks, and costs 40% less to run than Opus 5.
Elon Musk
@elonmusk
Congrats!
05:41 PM · September 22, 2026 · 29.3K views
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