Anthropic's Claude Opus 5 is the most capable AI model available today, according to several benchmarks, outperforming Fable 5 while costing less.
Opus 5 scored 61 on the Artificial Analysis Intelligence Index, which combines nine tests covering knowledge work, coding, scientific reasoning, and factual accuracy. That puts it just ahead of Claude Fable 5 (60), GPT-5.6 Sol (59), Kimi K3 (57), and Claude Opus 4.8 (56). Artificial Analysis worked with Anthropic to test the model before its public release.
In coding, Claude Opus 5 at "xhigh" paired with Claude Code shares first place on the Artificial Analysis Coding Index, which measures how well AI models handle programming tasks on their own, including finding and fixing bugs. On Terminal-Bench v2.1, which tests agents as autonomous engineers in real terminal environments, Opus 5 scored 89 percent at "max," matching the previous leader GPT-5.6 Sol.
Claude Opus 5 at "max" leads the Intelligence Index with 61 points. On the Coding Agent Index, Opus 5 with Claude Code and GPT-5.6 Sol with Codex share first place with 67 points. | Image: Artificial Analysis
For scientific reasoning, Opus 5 scored 53 percent on Humanity's Last Exam, a very difficult knowledge test covering many academic fields. That ties it with Fable 5. On CritPt, a physics benchmark from researchers at Argonne National Laboratory and UIUC, it again matches Fable 5 but trails GPT-5.6 Sol, GPT-5.5 Pro, and GPT-5.6 Terra.
