What changed
Google's documented August 17, 2026 shutdown date has passed for the Imagen 4 standard, fast and ultra endpoints in the Gemini API. The affected model IDs include imagen-4.0-generate-001, imagen-4.0-fast-generate-001 and imagen-4.0-ultra-generate-001. Google's current guidance points builders to Gemini 3.1 Flash Image and newer Nano Banana image-generation paths.
Why it matters
Production applications that pinned the old Imagen model IDs can now fail outright. Migration is not just a billing or naming change: builders need to verify request/response handling, image controls, safety behavior and output quality against the replacement model they select.
The deprecation has become a service cutoff
Google announced the deprecation in June and set August 17 as the shutdown date. Current model and deprecation documentation now describes Imagen 4 as shut down, so integrations that postponed migration have crossed from future risk into active availability risk.
The replacement is in the Gemini image family
Google's current documentation recommends Gemini 3.1 Flash Image/Nano Banana models for image generation. Builders should use the current stable model IDs from the Gemini documentation rather than copying older migration examples that may reference superseded preview IDs.
Migration requires behavioral testing
Even when the high-level use case remains text-to-image generation, replacement models can differ in API shape, supported controls, prompt handling, safety filtering, latency, image fidelity and price. A model-ID swap should therefore be validated with production prompts and acceptance criteria.