New Google Flow build now points to Nano Banana 2.1

A new internal build of Google Flow has shifted its model references from Nano Banana 2.5 Flash to Nano Banana 2.1, according to a teardown published by TestingCatalog. The change was not accompanied by any public announcement from Google, and no launch date has been indicated.

The version numbering shift is notable because 2.1 sits below 2.5, which might suggest this is not a straightforward linear progression. It is possible that 2.1 represents a separate model branch - perhaps one optimized for different performance characteristics, hardware targets, or use cases within Flow - rather than a simple downgrade or rollback.

Google Flow is the company's AI-powered video creation tool, built around its Veo video generation models. The Nano Banana codename refers to the image generation model that Flow draws on for still-image capabilities, and changes to it can affect the quality and style of frames produced within the tool. Iterative model updates of this kind are common during active development, and internal build references often shift several times before a version reaches a public release.

For now, the practical impact on end users is unclear, as the updated build has not rolled out broadly. Watchers of Google's generative media tools will likely keep an eye on further builds to see whether 2.1 stabilizes as the shipped version or gives way to yet another reference before launch.