Compare FLUX.2 Klein 4B from black-forest-labs and GPT-5.4 Image 2 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.
FLUX.2 Klein 4B and GPT-5.4 Image 2 are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
FLUX.2 Klein 4B, from black-forest-labs, has a 40,960-token context window and is priced at $0.014/megapixel on OpenRouter.
GPT-5.4 Image 2, from OpenAI, has a 272,000-token context window and is priced at $8/M tokens input, $30/M tokens output on OpenRouter.