Google's next Nano Banana is sitting in Flow, and its number just got smaller

Open Google Flow, click New character and you reach the screen that invites you to "build and reuse characters for consistent videos". Under it sits a dropdown that picks the image model drawing your character, and for most of this year it has offered three bananas: Nano Banana Pro, Nano Banana 2 and Nano Banana 2 Lite. On Wednesday 24 September a fourth line turned up at the bottom of that list in a screenshot posted by the leak-tracking account TestingCatalog. It read "Nano Banana 2.5 Flash", and the post asked one word: "Soon?"

Three days later the same account posted the same menu with a different label. "Nano Banana 2.5 Flash reference has been changed to Nano Banana 2.1 on Google Flow. A minor bump? Not available yet," TestingCatalog wrote on Saturday 27 September, alongside a short article saying the rename is a reason to "temper expectations". Google has said nothing about either name. There is no blog post, model card, API id, price or date, and as of this morning no Google page we could read mentions 2.1 at all.

What the screenshots actually show

Both pieces of evidence are screenshots from one account, and we have viewed both. What they show is more than a relabel. In the 24 September image, "2.5 Flash" sits last, under 2 Lite, with Nano Banana Pro as the default selection. In the 27 September image, "2.1" has moved up to sit between Nano Banana 2 and Nano Banana 2 Lite, and the default now reads Nano Banana 2. Someone at Google re-ordered the menu as well as renaming the entry.

Our reading, and it is an inference from a menu, is that 2.1 is being slotted in as a Flash-tier sibling of Nano Banana 2 rather than a successor to Pro. The name points the same way, because Nano Banana 2 is Google's Gemini 3.1 Flash Image model, launched on 26 February with output from 512px to 4K and up to five consistent characters in a scene, and a 2.1 reads naturally as a point release of that model.

Nobody outside Google has used it. TestingCatalog marked it "not available yet" both times, and creators who went looking came back empty. One Chinese-language user checked his own Flow account on 28 September and reported the menu was "still the old three". The post that reads most like a second sighting, from @nanyuan0412, attaches TestingCatalog's screenshot with its red arrow still on it. Every post we traced leads back to the same two images, so treat this as one source seen many times.

Why the smaller number is not a smaller model

The tempting story is that Google downgraded its ambitions along with the label, and the jokes write themselves. "Bro is delaying launches AND downgrading the model names now," @SahilPanhotra posted the day of the rename. The trouble is that a version number is the only evidence anyone has. Google renames products for marketing reasons all the time, and nobody has an output, a benchmark or a spec sheet for this model.

Plenty of people are trying to fill that gap anyway. Anonymous image models, nicknamed spicy-mayo on the Arena leaderboard in September and resplendent_flash in posts over the weekend, have been tied to Google by timeline guesswork alone. Spec sheets for "Nano Banana 2.5" on reseller blogs are Nano Banana 2's published specs with prices extrapolated on top. A LinkedIn post on 19 September predicted a partner launch that week, and it did not happen. Week-ahead lists put 2.1 on the slate for last week; Google shipped its Gemini 4 Argon text model on 30 September with no image model beside it.

What the rename does tell you is narrower. A label that was "2.5 Flash" on Wednesday and "2.1" on Saturday is a name still being argued over inside Google, which means the final name may change again before anything ships.

Meanwhile, the first banana went dark on Friday

The dated news in this family is happening at the other end. The original Nano Banana, the Gemini 2.5 Flash Image model that went viral in August 2025, was scheduled to shut down on the Gemini API (the paid developer access that apps and pipelines call) on Friday 2 October, according to Google's own deprecations page. That same page still names gemini-3.1-flash-image-preview as the replacement, a preview id it lists as already retired in June. Google's 30 June post on Nano Banana 2 Lite points developers to the Lite model instead, and it also says Lite is coming to Flow.

So the lineup is turning over at both ends at once, with the oldest model gone from the API and a new entry waiting in the menu of Google's filmmaking tool. If you still have scripts or third-party apps calling the old model id, check them today, because the deprecation table will not send you anywhere useful.

What it means if you make work

In practice, for anyone making work this week, the model in that dropdown is the start frame and the character sheet for every Veo shot you build in Flow, so a new default changes the look of your characters without asking. The leak turned up on exactly that screen, and when 2.1 appears, whether it lands as a quiet default or an opt-in, characters made on Nano Banana 2 and characters made on 2.1 may not match, and you do not want to find that out halfway through a project.

The cheap insurance is to lock what you have now. Save the reference sheets, prompts and seed images for the characters you rely on, and note which model drew each one, so you can run the same character through 2.1 on the first day it shows up and judge the difference side by side. That turns a surprise into a test you control.

The creator ask is already on record, and it is not for a point release. "Google really needs to get the true NANO BANANA 2 PRO out soon," the AI creator Brent Lynch wrote in a reply on 2 October, adding that 2.1 "looks like" another Flash model. If he is right, the version number is the least interesting thing Google could change, and the real question for character work is whether consistency across shots gets better. We will know when someone outside Google can open the menu and pick it.

Timeline

• Date: Aug 2025. What happened: Original Nano Banana (Gemini 2.5 Flash Image) goes viral; Source: Google blog recap
• Date: Thu 20 Nov 2025. What happened: Nano Banana Pro (Gemini 3 Pro Image) launches; Source: Google blog
• Date: Thu 26 Feb 2026. What happened: Nano Banana 2 (Gemini 3.1 Flash Image), 512px to 4K; Source: Google blog
• Date: Thu 28 May 2026. What happened: Stable API ids for Nano Banana 2 and Pro; Source: Gemini API changelog
• Date: Tue 30 Jun 2026. What happened: Nano Banana 2 Lite goes live, said to be coming to Flow; Source: Google blog; Gemini API changelog
• Date: Wed 24 Sep 2026. What happened: "Nano Banana 2.5 Flash" appears in Flow's character model menu; Source: TestingCatalog screenshot on X
• Date: Sat 27 Sep 2026. What happened: Same entry renamed "Nano Banana 2.1", moved up the menu, not usable; Source: TestingCatalog on X and its site
• Date: Wed 30 Sep 2026. What happened: Gemini 4 Argon announced with no image model; Source: Google blog
• Date: Fri 2 Oct 2026. What happened: Original Nano Banana scheduled to shut down on the Gemini API; Source: Gemini API deprecations page

Sources and what is unconfirmed: TestingCatalog's posts of 24 and 27 September (screenshots viewed) and its 27 September article; Google's Gemini API models, changelog and deprecations pages (read 2 and 5 October 2026); Google blog posts on Nano Banana Pro, Nano Banana 2, Nano Banana 2 Lite and Gemini 4 Argon; posts on X by @nanyuan0412, @SahilPanhotra and Brent Lynch. We could not see Flow's model menu ourselves because it loads only when signed in, and the last public sighting of the 2.1 entry is 27 September. Google has not confirmed the model, its name, tier, release date, resolution or price, and we did not contact Google for this piece. No link between Arena's anonymous models and Google is established.