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Anthropic: Claude Sonnet 5 vs OpenAI: GPT-5.5

On input price, Anthropic: Claude Sonnet 5 is ~2.5× cheaper. Verified 2026-08-23.

MetricAnthropic: Claude Sonnet 5OpenAI: GPT-5.5
Input / 1M$2.00$5.00
Output / 1M$10.00$30.00
Cache read / 1M$0.200$0.500
Context window1M1.1M
Max output128K128K

Monthly cost by workload

WorkloadAnthropic: Claude Sonnet 5OpenAI: GPT-5.5Cheaper
Chatbot$56.00$160.00Anthropic: Claude Sonnet 5
Coding agent$180.00$500.00Anthropic: Claude Sonnet 5
RAG pipeline$390.00$1050.00Anthropic: Claude Sonnet 5

Full details: Anthropic: Claude Sonnet 5 pricing · OpenAI: GPT-5.5 pricing