Compare Claude Opus 4.8 (Fast) from Anthropic and GPT-5.6 Luna 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 Opus 4.8 (Fast) and GPT-5.6 Luna are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
Claude Opus 4.8 (Fast), from Anthropic, has a 1,000,000-token context window and is priced by the provider serving it on OpenRouter.
GPT-5.6 Luna, from OpenAI, has a 1,050,000-token context window and is priced at $0.20/M tokens input, $1.20/M tokens output on OpenRouter.