Is Claude Opus 4.5 or Claude Sonnet 5.5 cheaper?
Claude Sonnet 5.5 is cheaper ($2 / 1M tokens input / $10 / 1M tokens output) vs Claude Opus 4.5 ($5 / 1M tokens input / $25 / 1M tokens output). Actual cost depends on your input/output token mix — estimate it with the pricing calculator.