FLUX.2 Klein 4B vs Nano Banana 2 (Gemini 3.1 Flash Image): side-by-side summary

FLUX.2 Klein 4B and Nano Banana 2 (Gemini 3.1 Flash Image) 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.

Nano Banana 2 (Gemini 3.1 Flash Image), from Google, has a 131,072-token context window and is priced at $0.50/M tokens input, $3/M tokens output on OpenRouter.

Context window

• FLUX.2 Klein 4B: 40,960 tokens
• Nano Banana 2 (Gemini 3.1 Flash Image): 131,072 tokens

Price

• FLUX.2 Klein 4B: $0.014/megapixel
• Nano Banana 2 (Gemini 3.1 Flash Image): $0.50/M tokens input, $3/M tokens output

Provided by

• FLUX.2 Klein 4B: black-forest-labs
• Nano Banana 2 (Gemini 3.1 Flash Image): Google

• FLUX.2 Klein 4B model details, providers and pricing
• Nano Banana 2 (Gemini 3.1 Flash Image) model details, providers and pricing