Is Claude Fable 5.1 or Claude Sonnet 5.5 cheaper?
Claude Sonnet 5.5 is cheaper ($2 / 1M tokens input / $10 / 1M tokens output) vs Claude Fable 5.1 ($10 / 1M tokens input / $50 / 1M tokens output). Actual cost depends on your input/output token mix — estimate it with the pricing calculator.