How to Write Prompts for Nano Banana

By PicGens editorial · Published Oct 1, 2026 · Updated Oct 1, 2026

Method: this guide summarizes reusable prompt patterns observed in public creator examples collected by PicGens. Results vary by model version, reference image and settings. Creator attribution does not grant a licence to reuse an accompanying image.

To prompt Nano Banana well, write a short editing brief instead of a list of adjectives: name the reference image and subject, say what must stay the same, state the one change you want, then add style, camera and light, and finish with one or two constraints. Change one thing per follow-up message.

What makes a Nano Banana prompt different?

Most Nano Banana prompts are written around a reference image. Instead of describing a whole new picture, you tell the model what to do with the photo you attached — restyle it, move the subject somewhere else, turn it into a figurine, swap a person, clean up a sketch. That is why the most reusable prompts in the PicGens Nano Banana collection read like instructions to an editor rather than descriptions of a painting.

This guide covers how to write those instructions. For where to run Nano Banana (the Gemini app, gemini.google.com or Google AI Studio) and the basic upload-and-edit workflow, see the companion guide on how to use Nano Banana linked below.

The five-part Nano Banana prompt structure

The public prompts that hold up best across different photos share the same order. Keeping that order makes it easy to see which sentence caused a problem when an edit misses.

Reference and subject. Say which image is the source and what in it matters: “the woman in the attached photo”, “the product in image 1”.
Keep. List what must not change — face, hairline, pose, product shape, label position. Put this before any change so it carries the most weight.
Change. State one primary edit directly: new outfit, new background, new medium, new season. One clear change beats five competing ones.
Style, camera and light. Add the look of the finished image: medium, framing, lens feel, colour palette and light direction.
Constraints. Finish with one or two checks that matter most, such as “no extra people”, “natural hands” or “no text”.

Example: rewriting a weak prompt

A loose prompt like “make me look cool in Tokyo, cinematic, 8k, amazing” gives the model nothing to protect and nothing specific to change. A rewritten version using the structure above: “Use the attached photo of me. Keep my face, hairstyle and glasses exactly the same. Place me on a rainy Shinjuku side street at night, wearing a black trench coat. Cinematic film still, 35mm lens feel, neon reflections on wet pavement, soft rim light from behind. No extra people in the foreground, no text.”

If the face drifts, edit only the keep sentence. If the street looks wrong, edit only the change sentence. That is the whole point of writing in blocks.

Prompt patterns for common Nano Banana jobs

The same structure adapts to the requests people search for most. Each pattern below links to a live PicGens collection where you can compare complete public prompts.

Photo restyle — keep the subject and pose; change medium, setting or colour grade. Example: “keep the person and pose, turn the photo into a 1990s film snapshot with warm grain and a slight light leak”.
Swap person or face swap — name the identity image first, list its features to keep, then say which person in the target image is replaced and what of that image stays. Only use photos of people who have agreed to it.
Logo concepts — quote the brand name exactly, choose one mark type (wordmark, monogram, emblem), describe shape and negative space, and ask for a flat mark on a plain background before any mockup.
Product shots — keep the product geometry and label, then change surface, camera angle and light. Verify the label text yourself afterwards.
Figurines and collectibles — keep the likeness, then add material (glossy PVC), base, packaging and studio lighting one block at a time.

How to handle text inside the image

Quote the exact words, keep them short and say where they go: “a small sign above the door reading ‘OPEN’”. Long sentences and small print are where generated lettering most often fails, so plan to add important copy in a design tool and to proofread every character the model renders. The newer Nano Banana versions are generally described as handling text better, but PicGens has not measured that, so check the result rather than relying on the version label.

Fix the most common Nano Banana prompt failures

When a result misses, name the failure before rewriting. Most fixes are about removing a competing instruction, not adding more words.

Identity drift — move the keep sentence to the start, remove descriptions of the face, and use a sharper, front-facing reference.
Old background leaks into the new scene — describe the new background as a complete scene and say the original background is replaced.
Garbled text — quote fewer words, specify position and size, and verify every character.
Overloaded prompt — cut adjectives until only subject, keep, change, one light direction and one constraint remain, then add details back one at a time.
Results vary between runs — keep the reference, prompt and aspect ratio fixed and change one block per attempt so you can tell what helped.

Do Nano Banana Pro and Nano Banana 2 need different prompts?

The keep/change structure is a sensible starting point for every version, and most public prompts in the PicGens collections are written that way. PicGens has not run a controlled comparison between versions, so treat any difference in how they follow a prompt as something to test with your own permitted images. The comparison pages linked below give a decision framework rather than a benchmark.

Frequently asked questions

How long should a Nano Banana prompt be?: Usually two to five sentences: reference, what to keep, one change, the look, and a constraint. Longer prompts are harder to debug; add detail only when it changes what the image should show.
Do I need to upload a photo to prompt Nano Banana?: No, it also generates from text alone, but most popular Nano Banana prompts are edits of an attached photo because that is where the keep/change structure is most useful.
How do I keep a face consistent across Nano Banana edits?: Put the identity sentence first, avoid re-describing the face, use a clear reference and change only one thing per message. Compare each result with the original before continuing.
Can I copy prompts from PicGens into Nano Banana?: Yes. Copy a prompt from the Nano Banana collections, attach your own permitted photo if it calls for one, and replace the subject first. Public examples are starting points, not guaranteed outputs.