Imagen 4 Fast vs Nano Banana Pro
Google's Imagen 4 Fast and Google's Nano Banana Pro both target image generation, but they price and behave differently. Here is the side-by-side.
Pricing checked against provider documentation on . How we verify
The short answer
Imagen 4 Fast is the cheaper option — roughly 6.7x less on a blended workload, and it suits cheapest speed-first generation. Nano Banana Pro justifies its premium when you need multi-image compositing and iterative edits.
Google • Imagen 4
$0.02 / $
/ image (input / output)
Google's efficiency tier for image generation, aimed at high-volume pipelines where throughput matters more than the last increment of quality. Fine for thumbnails, placeholders, and drafts; step up to the Gemini image models when typography or compositing is the point.
Google • Gemini Image
$0.13 / $
/ image (input / output)
Google's premium image tier, aimed at workflows that feed several source images in and refine the result across turns rather than generating one-shot. The most expensive option in this table at 4K, and the batch lane halves it for anything that does not need a synchronous response.
Input price
Nano Banana Pro is 6.7x the price than Imagen 4 Fast on input tokens.
Specification comparison
| Attribute | Imagen 4 Fast | Nano Banana Pro |
|---|---|---|
| Input (/ image) | $0.02 | $0.13 |
| Output (/ image) | — | — |
| Cached input | — | — |
| Context window | — | — |
| Max output | — | — |
| Native reasoning | No | No |
| Knowledge cutoff | — | — |
| Relative latency | low | medium |
| Open weights | No | No |
| API model ID | imagen-4.0-fast-generate-001 | gemini-3-pro-image |
| Status | stable | stable |
Imagen 4 Fast: 1K resolution.
Nano Banana Pro: 1K–2K resolution on the standard tier; 4K is $0.24. Batch and Flex lanes cut both roughly in half, to $0.067 and $0.12.
Choose Imagen 4 Fast if…
- High-volume thumbnails
- Draft and placeholder imagery
- Rapid prompt iteration
- Catalogue and listing images
Choose Nano Banana Pro if…
- Compositing multiple source images
- Iterative art direction
- High-resolution brand assets
- Complex edit chains
Frequently asked
Is Imagen 4 Fast or Nano Banana Pro cheaper?
Imagen 4 Fast is cheaper. On a blended 3:1 input-to-output workload it costs about 6.7x less than Nano Banana Pro.
Which has the larger context window, Imagen 4 Fast or Nano Banana Pro?
Both accept up to — tokens, so context is not a differentiator here.
Should I use Imagen 4 Fast or Nano Banana Pro?
Pick Imagen 4 Fast for cheapest speed-first generation. Pick Nano Banana Pro for multi-image compositing and iterative edits. If cost dominates the decision, Imagen 4 Fast wins; if you need the capability ceiling, benchmark both on your own evals before committing.