Model
Claude Opus 5.5.
Power
£££
API cost
by Anthropic · released 22 September 2026
In plain English
Anthropic's strong everyday model for demanding work, at half Fable's price.
Good for
Coding agents and professional work with lots of steps that depend on each other.
Things to be aware of
Compare what it costs to get the task finished, including retries and checking, rather than comparing token prices alone.
What Anthropic says
“Opus 5.5 “leads in agentic coding and knowledge work”.”
What everyone else says
TechCrunch noted that Anthropic claimed Fable-level performance at a substantially lower running cost than Opus 5. TechCrunch, 22 September 2026
- Context window
- 1.0M tokens
- Knows up to
- June 2026
- Run it yourself
- No, online only
- API price
- $4 in / $20 out
- per million tokens