Google Flow Reference Points to Nano Banana 2.1 as Official Docs Still Center on Nano Banana 2

A Google Flow model reference has been observed changing from Nano Banana 2.5 Flash wording to Nano Banana 2.1, suggesting a possible minor update in Google's image-generation lineup, but Google has not published a public release note for Nano Banana 2.1 and the model is not available yet. The confirmed public baseline remains Nano Banana 2, officially Gemini 3.1 Flash Image, which Google says is now the default image-generation model in Flow and available to all Flow users for zero credits.