Good Nano Banana prompts specify the job, subject, composition, constraints, and edit boundary without burying the priority. Treat every example here as a template until you run it against the exact model version and settings available to your account.
A practical evaluation method
- Change one prompt variable at a time.
- Keep a failure log for text, anatomy, layout, identity, and unwanted edits.
- Save the model ID, parameters, references, and accepted output with each prompt revision.
Prompting Nano Banana Pro
Nano Banana Pro (gemini-3-pro-image-preview) is Google's flagship image model — standout for ~94% in-image text accuracy, Search grounding, and native 4K. Good prompts lean into those strengths. Model overview: Nano Banana API guide.
A Prompt Structure That Works
Order: subject → composition → style → text (quoted) → resolution.
Infographic of the water cycle, clean flat vector style,
labeled arrows, three panels left-to-right,
title text "THE WATER CYCLE", labels "Evaporation", "Condensation", "Precipitation",
4K, high contrast, legible typographyNail the Text (Its Superpower)
- Quote every string exactly in quotes; the model renders what you quote.
- Specify placement ("title top-center", "caption bottom") for multi-text layouts.
- Nano Banana Pro handles long passages and multilingual text better than most — still eyeball rare glyphs.
Use Grounding for Factual Images
Because it can ground on Search, Nano Banana Pro is strong for images that must be correct — accurate diagrams, real landmarks, current logos/styles. Ask for factual accuracy explicitly ("accurate map of…", "correct anatomy of…").
Generate at the Right Resolution
curl -X POST https://api.linkmodel.ai/api/v1/image-generation \
-H "Authorization: Bearer $LINKMODEL_API_KEY" -H "Content-Type: application/json" \
-d '{ "model": "gemini-3-pro-image-preview", "prompt": "<your structured prompt>", "size": "4K" }'4K costs more than 1K/2K — use it for hero assets, 2K for web. Submit, get a task_id and price, poll for the image. Confirm parameters in the docs.
Editing
Provide a source image and describe the change ("replace the headline with 'SALE', keep everything else"). For heavy layer-by-layer editing, also consider Seedream; see best image editing API.
Tips
- One clear subject; describe composition (negative space, panels, grid).
- Be explicit about text — quote it, place it.
- Draft at 1K/2K, finalize at 4K to save cost — cheapest image API.
- Compare with the cheaper premium option in Seedream vs Nano Banana Pro and Nano Banana Pro vs GPT Image 2.
Bottom Line
Structure prompts, quote and place your text, lean on grounding for factual images, and right-size resolution. That's how you get Nano Banana Pro's ~94% text quality reliably. Full field: best AI image generation APIs.
Start free with a $1 credit and test your prompts.
