Google announced on 6 October in the Gemini API release notes that the model is generally available: according to the company it keeps Flash-level speed and cost efficiency and improves the wide 1:4, 4:1, 1:8 and 8:1 formats up to 4K. The old gemini-3.1-flash-image is deprecated, with no shutdown date.
- gemini-nano-banana-2.1 is generally available from 6 October: an update to Nano Banana 2 that, according to Google, keeps Flash-level speed and cost efficiency.
- Better wide formats 1:4, 4:1, 1:8 and 8:1 at 1K, 2K and 4K, plus better character consistency across turns and better text in the image, in Google’s words.
- gemini-3.1-flash-image is deprecated, with no announced shutdown date. Google says to migrate to the new model.
8:1 is a strip: eight times wider than it is tall. That is the format you want for a website header or, if it is big, a roadside billboard.
Google says Nano Banana 2.1 makes strips like that significantly better: 8:1, 1:8, 4:1 and 1:4, at 1K, 2K and 4K.
One image cut for a billboard, a header and a banner rarely survives intact: in every format the hero sits somewhere else, and in one of them he loses his head. That is why the strip is for people making a campaign, not for playing in a chat.
The second one is “character consistency across turns”. In human terms: the campaign’s hero is the same person on the third picture as on the first. But that is Google’s claim. The note has no example and no number.
Anyone already on gemini-3.1-flash-image will be switching the model name anyway: the old one is deprecated, with no shutdown date yet. Switch it in a test environment and run a one-evening test there: a hero you already have, four turns, 8:1. If the face holds, Google’s claim has passed its first check.