Anthropic · Released September 22, 2026
Claude Opus 5.5
Anthropic's most capable general release (September 22, 2026), aimed at long-running agentic coding with a 1M-token context window. Paid; claude.ai's free tier remains the free way in.
Best for: people deciding whether this model's paid plan is worth it — and looking for the free way into the same family.
What it costs
Included with Claude Pro and Team plans; API usage-based. Anthropic's flagship tier is not on the free plan.
What it is
Claude Opus 5.5 is the top of Anthropic's Claude 5.5 family, released September 22, 2026. Anthropic describes it as its most capable general release model, aimed at long-running agentic coding and knowledge work, with a context window of one million tokens — enough to hold very large codebases and document sets in a single conversation.
It sits above Claude Sonnet 5.5 and the smaller, faster Claude Haiku 5.5 released in October. Reviewers place it at or beyond the capabilities of Anthropic's earlier Claude Fable and Mythos generations, per coverage of the 5.5 family rollout.
Like every frontier model right now, it is a paid product: Claude Pro is the consumer plan that includes it. The free tier at claude.ai still gives daily access to the Claude family's capable mid-tier models at no cost — which is what most people evaluating Opus 5.5 news actually need.
The free way into this family
claude.ai's free tier gives daily access to the Claude family without a card — Opus 5.5 itself is reserved for paid plans, but the free models share the same training lineage and voice.
Free Anthropic tools, hand-checked
Genuinely free listings from the same ecosystem — each verified against the provider's own pages:
Claude
Anthropic · Claude Sonnet 5
Anthropic's AI assistant for writing, research, and analysis — free to start at claude.ai, with paid Pro and Max plans for heavier use.