Free tool · Runs in your browser · No sign-up
Nano Banana Prompt Generator
Assemble a complete prompt for Google’s Nano Banana image model from tested phrase blocks. Pick a mode, choose the look, copy the result into Gemini. In Photo Edit mode the generator automatically adds the preserve-the-subject guard block that stops Nano Banana from redrawing faces and backgrounds you wanted untouched. And when you need the same character across many images, the Character Kit mode extends that guard into a full consistency workflow: a character sheet, an identity-lock block, and a change-only-this edit template.
How this generator builds a prompt
Every option maps to a phrase block we validated in our own prompt gallery and photo-editing tests. The blocks are combined in a fixed order that Nano Banana parses reliably: task → subject → style vocabulary → lighting → constraints. Two details do most of the work:
- The preserve-the-subject guard. In Photo Edit mode the prompt explicitly lists everything Nano Banana must not change — face, hairstyle, pose, clothing, composition, background objects. Without this block, edits tend to “drift”: the model helpfully regenerates parts of the image you wanted intact. With it, edits stay surgical. This is the single biggest quality lever we found while testing photo-editing prompts.
- Material vocabulary for the figurine look. The viral collectible-figurine aesthetic is mostly a vocabulary trick: scale (“1/7 scale”), finish (“glossy PVC”, “matte resin”), and staging (“acrylic base”, “collector blister box”). Naming all three pins the style; skipping them gets you a generic 3D render.
The generator is a starting point, not a ceiling. After copying, tweak nouns and lighting words directly in Gemini — conversational follow-ups like “same image, warmer light” work well once the first render is close.
Character consistency: why the face keeps changing
The most common Nano Banana complaint reads the same way every time: “I only wanted to change the outfit, and the face changed completely.” The cause is simple — every attribute your prompt leaves unspecified is fair game to regenerate. Ask for a new outfit and say nothing about the face, and the model re-samples the whole figure; a few percent of drift per feature adds up to a stranger wearing your new clothes. The Character Kit mode packages the community workarounds into three templates that extend the same guard-block idea used in Photo Edit mode:
- Character sheet first. Generate front, three-quarter, and profile views in one neutral setting before doing anything creative. Each view repeats the locked attributes verbatim — verbatim repetition, not paraphrase, is what makes the three renders match. These become your reference images for every later edit.
- Identity lock at the top of every prompt. A short reusable block that names the character and pins hair, eyes, clothing, age, and art style before the actual request. It is the same discipline as the “Keep X identical” lock for multi-turn editing: restate what must not change in every turn, because the model does not remember your constraints from the last one.
- Delta edits only. When you want a change, describe only the increment: “same character, same face, same hair — change only: the jacket.” Everything not mentioned is explicitly frozen. This is the single most effective pattern we found while testing face-preserving edit prompts.
No prompt guarantees pixel-perfect identity every time — but locked attributes plus delta-only edits turn “random stranger each render” into “recognizably the same character with occasional retries”. For the general-purpose version of this structure, see the Nano Banana master prompt template.
Worked examples from our library
If you want finished, tested prompts instead of building your own, start with these collections — each shows the exact prompt text and the kind of result to expect:
- Nano Banana prompts for LinkedIn profile pictures — the portrait-mode presets here come from that set.
- Nano Banana prompts for realistic photos — realism vocabulary the Photo Edit mode reuses.
- Nano Banana product photography prompts — the Product Shot mode in a deeper form.
- Google Nano Banana prompts: the full guide — what the model is and where it fits in Gemini.
- Gemini prompts to improve image quality — fix blur, noise and low light before styling.
More free Gemini tools
- Aspect ratio canvas generator — when Gemini ignores your 16:9 request and returns squares.
- Image fix prompt picker — repair blurry, plastic, or warped output with paste-ready blocks.
FAQ
What is a Nano Banana prompt generator?
It is a free tool that assembles a complete, well-structured prompt for Google’s Nano Banana image model (part of the Gemini family). You pick a mode — photo editing, 3D figurine, portrait, product shot, or the character consistency kit — choose the options you want, and the generator combines tested phrase blocks into one prompt you can copy straight into Gemini.
Why do Nano Banana prompts need a “preserve the subject” block?
Nano Banana’s biggest failure mode in photo editing is unrequested changes: it may redraw faces, alter poses, or regenerate backgrounds you wanted untouched. A guard block that explicitly lists what must not change (face, pose, clothing, composition, background objects) dramatically improves edit fidelity. The generator adds this block automatically in Photo Edit mode.
What makes the 3D figurine style work?
The viral figurine look comes from material and packaging vocabulary: describing the subject as a collectible figure at a specific scale (commonly 1/7), naming the material finish (glossy PVC, matte resin, vinyl), and placing it on a base or inside collector packaging. The generator exposes each of these as options so you can dial the look precisely.
How do I keep the same character consistent across multiple Nano Banana images?
Use the Character Kit mode. It turns your character’s locked attributes (hair, eyes, clothing, age, art style) into three reusable templates: a 3-view character sheet (front, three-quarter, profile) to generate reference images, an identity-lock block you paste at the start of every later prompt, and a delta-edit template that describes only the one thing you want changed. Repeating the locked attributes verbatim in every prompt is what keeps the character recognizable.
Why does Nano Banana change the face when I only asked for a new outfit?
Because anything your prompt does not pin down is fair game to regenerate. When you say “change the outfit” and nothing else, the model re-imagines the whole figure — face included — and small sampling differences add up to a stranger wearing the new clothes. The fix is the delta-edit pattern: state “same character, same face, same hair — change only: [the outfit]” and explicitly forbid touching everything else. The Character Kit mode writes that prompt for you.
Can I use these prompts with models other than Nano Banana?
Mostly yes. The output is plain descriptive English, so Midjourney, DALL-E, and other image models will understand it. The preserve-subject guard block is most useful in editors that take an input image, which is Nano Banana’s specialty inside Gemini.
Is this tool free? Does it store my prompts?
Free, no sign-up, and everything runs in your browser — nothing you type is sent to a server. Copy the result and paste it into the Gemini app.