Compare Claude Sonnet 4.5 from Anthropic and GPT-5 Pro from OpenAI on key metrics including benchmarks, price, context length, and other model features. Access both models and hundreds of others through the OpenRouter API.
Claude Sonnet 4.5 and GPT-5 Pro are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
Claude Sonnet 4.5, from Anthropic, has a 1,000,000-token context window and is priced at $3/M tokens input, $15/M tokens output on OpenRouter.
GPT-5 Pro, from OpenAI, has a 400,000-token context window and is priced at $15/M tokens input, $120/M tokens output on OpenRouter.