A Simple Guide: The “Red box Trick” for AI Photo Edits with Nano Banana

This guide shows you a simple trick to get better, more exact edits from Gemini's flagship image editing model "Nano Banana". It helps the Gemini understand exactly what you want to change.

Follow this guide to use this Red Box Trick:

Step 1: Open Your Image

Open your photo in any basic image editor (like Paint, Photoshop, or even a phone markup tool). You just need a tool that lets you draw boxes and write text.

Step 2: Draw Red Boxes and Add Notes

Draw a red box around the exact area you want to change. Inside (or next to) each box, write a very short, simple command.

• Example: Draw a red box around a person's eyes and write, "Make eyes open."
• Example: Draw a red box around a drink in someone's hand and write, "Change this to an ice cream cone."

You can do this for many different parts of the photo all at once.

Step 3: Give the AI Your Prompt

Now, upload your image (with the red boxes and text on it) to the AI model. Instead of a simple prompt, use a more detailed one.

Here is a great prompt to use:

"Read and interpret all red text annotations within the image. For each annotation, apply the requested modification only to the corresponding highlighted area. Do not alter or modify any other part of the image. Ensure that all edits blend naturally and look realistic, preserving original lighting, shadows, and textures. After applying all modifications, remove every red text annotation and its corresponding red box so that no editing marks remain visible in the final image."

Thanks to Fotie M. Constant for this prompt

Step 4: Run the AI

Let the Gemini run edits with Nano Banana. It will read your notes, make the changes only in the boxes, and then remove your red boxes and text, leaving you with the final, edited image.

Tips for the Best Results

• Keep notes short: Use simple phrases like "Add a hat" or "Make this blue." Long sentences can confuse the AI.
• Make boxes tight: Draw your box closely around the item you want to change. A box that is too big might cause the AI to change more than you want.
• Tell the AI to clean up: Always include "remove the red text and boxes" in your prompt, just as in the example above.
• Try other colors: If red doesn't seem to work (maybe your photo is very red), try using a different bright color like green or yellow.