Free local background prompt builder

Change the background, not the subject

Describe the new setting and get a structured prompt that protects the foreground subject while matching perspective, lighting, shadows, reflections, and grain. No image is uploaded or generated until you choose the paid editor.

Runs in your browserNo sign-up requiredUses zero generation credits

Step 1

Define the protected subject and new setting

No AI call

What must remain in the foreground?

Describe the new background

Name the location, surfaces, time of day, atmosphere, and anything that must not appear.

Protected subject details

Perspective, light, and edge matching

Failures to avoid

Step 2

Your background change prompt

SOURCE: Use the uploaded portrait as the source image and treat the person as the protected foreground subject.

CHANGE ONLY: Replace only the background with a quiet modern studio in warm neutral colors, with a clean floor-to-wall transition and no extra people or text.

PRESERVE: Keep the same facial structure, skin tone, age, hairstyle, expression, clothing, pose, hands, body proportions, subject scale, crop, and camera angle.

INTEGRATE: Match the original lens perspective, camera height, depth of field, light direction, color temperature, edge light, contact shadows, reflections, and image grain. The subject must look naturally photographed in the new setting.

AVOID: Do not retouch the face, change identity, redesign clothing, change anatomy, add people, alter the crop, or create a halo around the subject.

Keep every non-background element unchanged except for the physically necessary edge light, color spill, contact shadows, and reflections that integrate the protected subject into the new background.

Open in editor

Recommended model

Nano Banana 2

1K draft

8 credits · about $0.23–$0.40

2K working edit

12 credits · about $0.34–$0.59

Building and copying the prompt is free. Credits are used only if you continue to image generation.

The background replacement formula

A believable edit needs more than a place name

A useful prompt gives the background permission to change, locks valuable foreground details, and explains how the old and new pixels should meet.

This structure follows Google's guidance to describe the setting and refine details incrementally: official Gemini Image prompt guide.

Name the new setting

Describe location, surfaces, time, atmosphere, and excluded objects instead of saying only “change the background.”

Lock the subject

Protect identity, product geometry, markings, pose, crop, camera angle, text, and other details that carry value.

Match the scene

Ask for consistent perspective, depth of field, light direction, edge light, color spill, shadows, reflections, and grain.

Reject drift early

Compare the result with the source at low resolution. Return to the source if several protected details changed.

Repair the visible failure, not the whole image

Submitting the same prompt again spends credits without narrowing the problem. Add one correction that names the failed boundary.

See all photo editing repair prompts

Visible failureNarrow repair instruction

Halo around the subjectMatch fine edges, background color spill, edge light, grain, and depth of field; remove the cutout outline.

Face or product changedRestore the protected subject from the original source and change no facial or product geometry.

Subject looks pasted inAdd a physically consistent contact point, contact shadow, reflection, scale, and camera perspective.

Light directions conflictKeep the subject geometry unchanged and match only edge light, color temperature, and shadow direction to the new scene.

Crop or subject scale changedRestore the original framing, subject size, camera height, and lens perspective; modify only background pixels.

Background prompt questions

What is free, what costs credits, and what a prompt can and cannot protect.

Is this Nano Banana background changer free?

Building and copying the prompt is free, local, and requires no account. Image generation is not free: the editor shows the exact credit charge and approximate one-time-pack cost before a request starts.

Which Nano Banana model should I use?

Start with Nano Banana 2 at 1K for an inexpensive draft, then use 2K after the subject boundary and scene integration look correct. Move to Pro only for a specific precision problem that remains.

Will the prompt keep the same face exactly?

No prompt guarantees biometric identity. A detailed preservation block reduces unwanted drift, but you still need to compare the face, hairline, ears, teeth, hands, clothing, and proportions with the source.

Can I request a transparent background?

You can request subject isolation or a plain catalog background, but verify edge quality and the actual exported format. A visually plain background is not automatically a file with a real alpha channel.

Image generation is paid

Check the cost before replacing the background

The editor receives the full prompt and selects Nano Banana 2, but it does not generate automatically. You can inspect the source, model, resolution, credits, and estimated cost first.

See credit packs

General prompt generator 20 photo editing prompts Product photography workflow