Claude Fable 5 Achieves Higher Accuracy Than GPT-5.5 on Challenging Math Problems
Anthropic's Claude Fable 5 has demonstrated superior performance in mathematical problem-solving, achieving 88% accuracy on FrontierMath's most challenging tier. This places it 13 points ahead of OpenAI's GPT-5.5, which scored approximately 75% on the same benchmark. The result highlights a significant acceleration in AI's mathematical capabilities, marking a substantial improvement from previous models like Opus 4.5.
Anthropic's Claude Fable 5 has reportedly achieved an 88% accuracy rate on the most difficult tier of FrontierMath problems. This performance positions Claude Fable 5 with a 13-point lead over OpenAI's GPT-5.5, which recorded approximately 75% accuracy on the identical benchmark.
This advancement represents a considerable leap in AI's mathematical proficiency. Earlier in 2026, the Opus 4.5 model, a predecessor, registered an accuracy rate below 10% on the same rigorous FrontierMath tier.
The continuous improvement suggests an accelerating pace in the development of AI systems for complex mathematical tasks. According to The Decoder AI, the pace of improvement in AI math continues to accelerate.
