Nano Banana 2: Migrate Gemini Image Code by June 25

Google just set a hard deadline that quietly breaks a lot of production code. On June 25, 2026, the Gemini API shuts down its preview image-generation models, including gemini-3.1-flash-image-preview and gemini-3-pro-image-preview. If your app still calls those IDs, image generation returns errors that day, with no grace period.

This is not a rumor. The Gemini 2.0 text models already went dark on June 1, and video generation models follow on June 30. The fix is small but real: the generally available replacements, nicknamed Nano Banana 2 and Nano Banana Pro, have shipped since May 28 and you migrate by deleting one word from a string. The catch is that the GA models also added a few config options, so it is worth understanding what you are switching to rather than blindly editing strings.