Nano Banana Prompt Generator
Image editing goes wrong when the model changes more than you asked. Describe the edit and PromptVibe writes a prompt that says what to change, what to keep exactly as it is, and how the result should look — free.
Nano Banana is the nickname for Google's Gemini image generation and editing model. Editing prompts work best when they name three things: the specific change you want, what must be preserved unchanged, and the look of the finished image. Naming what to preserve is what stops an edit turning into a regeneration.
How Nano Banana prompts differ
- Editing is subtraction, not description: A generation prompt describes a whole image. An editing prompt describes a delta. Re-describing the entire picture invites the model to rebuild it, and the parts you liked disappear.
- Preservation has to be explicit: "Keep the subject's face, pose and clothing exactly as they are" is doing more work than any other sentence in an editing prompt. Without it, everything is fair game.
- One edit at a time is more reliable: Chaining several small edits — change the background, then adjust the light, then remove the object — gives you a checkpoint after each one. Bundling them makes failures hard to attribute.
- Conversational refinement works: These models handle follow-up instructions well. "That is close, but make the shadow softer and leave everything else alone" is a legitimate and effective second step.
Techniques that work
- Use the change / preserve / result structure. State the change, then what to preserve, then how the result should look overall. Three sentences beats one long one.
- Be specific about location. "Remove the car in the lower right" is actionable. "Remove the car" is ambiguous when there are three.
- Match the lighting when compositing. When adding or replacing an element, say where the light comes from so the addition sits in the scene instead of on top of it.
- Ask for a subtle version first. Models overshoot. Requesting a restrained change and then pushing further is faster than pulling an exaggerated result back.
Example Nano Banana prompts
Background replacement — Change / preserve / result
Change: replace the cluttered office background with a plain warm-grey studio backdrop. Preserve: keep the subject's face, hair, pose, clothing and the framing exactly as they are — do not alter the person in any way. Result: an even, slightly out-of-focus backdrop; relight the edges of the subject so the light direction matches the new background (soft light from the upper left). Natural skin tones, no added glow.
Object removal — Change / preserve / result
Change: remove the parked bicycle in the lower-left corner and fill the space with the same pavement texture. Preserve: everything else in the frame, including the shopfront, the two people on the right, and the existing shadows. Result: a seamless pavement with matching tone and grain; no smudging, no blurred patch, no invented objects in the gap.
Style adjustment — Change / preserve / result
Change: warm the overall colour grade slightly and lift the shadows so detail is visible in the darker areas. Preserve: composition, subject, and all objects exactly as they are — this is a colour adjustment only. Result: a gentle warm grade, roughly the feel of late-afternoon light, with no clipping in the highlights and no colour cast on skin tones. Subtle, not stylised.
Test it before you trust it
A prompt that reads well is not the same as a prompt that works. The Compare AI Lab runs the same prompt through up to three models side by side so you can see which one actually handles your task, and the A/B tester scores two versions of a prompt against criteria you choose. Free members get a comparison every day.
Limitations
- PromptVibe is an independent tool and has no affiliation with Google.
- "Nano Banana" is a community nickname for a Google image model, not an official product name.
- Editing results vary with the source image; a structured prompt improves consistency but does not guarantee an outcome.
Frequently asked questions
What is Nano Banana?
Nano Banana is the widely used nickname for Google's Gemini image generation and editing model, which became known for handling targeted edits to an existing image while keeping the rest of it intact.
Why does the model change things I did not ask it to change?
Because the prompt did not say what to preserve. An editing prompt should always contain an explicit preservation clause naming the subject, pose, framing and anything else that must not move.
Should I make several edits in one prompt?
Usually not. Separate edits give you a checkpoint after each one, so when something goes wrong you know which instruction caused it. Chain them as follow-up messages instead.
Is this an official Google tool?
No. PromptVibe is independent and has no affiliation with Google.