Which Nano Banana (Gemini image) model should you use for character consistency and references, and what are the limits?

Gemini API docs (captured 2026-10-23) list five Nano Banana models: Nano Banana 2.1 (gemini-nano-banana-2.1; recommended workhorse: Flash-level speed/cost with improved quality, text rendering, multi-turn consistency, Google Search grounding, 1K/2K/4K); Nano Banana 2 Lite (gemini-3.1-flash-lite-image; fastest/cheapest, "not optimized for multiple reference inputs or multi-turn sequential editing"); Nano Banana 2 (gemini-3.1-flash-image; previous workhorse, 4K, multi-reference consistency; new projects should use 2.1); Nano Banana Pro (gemini-3-pro-image; premium for complex tasks, localization, brand consistency, precise control); Nano Banana (gemini-2.5-flash-image; legacy, migrate to 2 Lite). All outputs carry SynthID. Up to 14 reference images can be mixed; the per-model table lists object-fidelity references of up to 14 / 10 / 6, character-consistency references of up to 4 or 5 (N/A for Lite), and up to 3 style references (one model only) - the flattened text does not reliably tie each number to a model column, so check the rendered table before relying on a specific model's cap. Practical: for character sheets/turnarounds use 2.1 or Pro with multi-turn editing; Lite is for volume. Arena preference (C3-B367-01) places Nano Banana 2.1 just behind the GPT-Image-2.5 variants. Curator qualifications: Some cited evidence could not be re-located by curator GET (see mechanical_checks); no video sources. Provider documentation as served 2026-10-23; models, limits and prices change without notice. SynthID sentence located (spacing differed). Limitations: Per-model column mapping uncertain in extraction; pricing per image not captured. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

{
  "citations": [
    {
      "url": "https://ai.google.dev/gemini-api/docs/image-generation",
      "note": "line 51; line 55-56; line 71; reference table"
    }
  ]
}