Anthropic · Claude Opus line · flagship
Claude Opus 4.6 was released by Anthropic on February 5, 2026, as a flagship model in the Claude Opus line.
Anthropic's Opus 4.6: a big jump on brand-new reasoning puzzles and the first Opus that can read 1M tokens of text at once — but its score on fixing real software bugs (SWE-bench Verified) is unchanged.
Compared with Claude Opus 4.5 · the model it replaces
Solves far more puzzle-style problems it has never seen before
ARC-AGI-2 — reasoning through brand-new problems, not memorized ones
68.8%
▲ up from 37.6% · +31 points
First Opus that can read 1M tokens of text at once
Context window — how much text it can hold in one go
1M tokens
✦ new in Opus 4.6 (in beta, Claude API only at launch) — earlier Opus models held less
Fixes real software bugs at the same rate as before
SWE-bench Verified — fixing real bugs in real software projects
80.8%
no change from Opus 4.5 — was 80.9%
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Claude Opus 5.5 is the current model in this line. The card shows how long it has been since the last release against the line's usual gap and its recent ones — the rhythm, not a date.
Latest: Claude Opus 5.5 · Sep 22, 2026
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