Claude Fable 5 outpaces GPT-5.5 by 13 points on FrontierMath's toughest problems
Anthropic's Claude Fable 5 has achieved an impressive 88 percent accuracy on the most challenging problems in FrontierMath, significantly outperforming OpenAI's GPT-5.5, which scored around 75 percent. This marks a substantial improvement from the previous model, Opus 4.5, which had an accuracy below 10 percent in early 2026.
WPN Brief
- What Happened
Anthropic's Claude Fable 5 has achieved an impressive 88 percent accuracy on the most challenging problems in FrontierMath, significantly outperforming OpenAI's GPT-5.5, which scored around 75 percent. This marks a substantial improvement from the previous model, Opus 4.5, which had an accuracy below 10 percent in early 2026.
- Why It Matters
The release of Claude Fable 5 is pivotal for Anthropic, showcasing its advancements in AI capabilities and solidifying its position in the competitive AI landscape, particularly in complex mathematical problem-solving.
- The Bigger Picture
This development reflects a broader trend in AI where rapid advancements are becoming commonplace, raising discussions about the implications of such technologies in various fields, including software engineering and cybersecurity, as well as concerns regarding the limitations and ethical considerations surrounding AI models.