Anthropic's Fable 5.1 Cuts Costs While Boosting Performance

Anthropic's latest AI model, Fable 5.1, has been released with impressive improvements over its predecessor, Fable 5.

The new model boasts a 90% coverage on the ARC-AGI-2 benchmark at a significantly lower cost per task - 32% less than Fable 5, which had a verified price tag of $5.45 per task.

This represents a notable step up from Fable 5's verified score of 89.2%, and also shows improvement on other benchmarks such as Terminal-Bench 4.0 and Terminal-Bench-Science 0.1, where Fable 5.1 more than doubled its predecessor's performance.

The cost reduction is partly due to smarter caching, with Anthropic cutting cache-read pricing by 75%, from $1.04 per million tokens to $0.25 per million tokens.