I Built a Free Tool to Remove Invisible AI Watermarks from Google Gemini Images

Denuwan Lahiru — Sun, 08 Mar 2026 23:38:39 +0000

Every image generated by Google Gemini, Imagen 2, and Imagen 3 has a hidden watermark called SynthID — invisible to your eyes but detectable by AI content scanners.
This can flag your images as AI-generated, get them suppressed on social platforms, or rejected by clients.
So I built RemoveBanana 🍌 — a free, open-source tool to remove it.

🔬 How It Works

Most "watermark removers" use AI/blurring → destroys quality.
RemoveBanana uses math. The watermark is applied via alpha blending:
watermarked = original × (1-α) + watermark × α

We reverse it:
original = (watermarked - watermark × α) / (1-α)

Result: exact original quality restored. Zero loss.

⚡ 3 Ways to Use It

1. Web App (No Install)

Visit removebanana.eu.cc → upload → download clean image in 3 seconds. Everything runs in your browser — images never leave your device.

2. npm Package


bash
npm install removebanana
javascript
const rb = require('removebanana');
await rb.removeWatermark('input.png', 'output.png');

3. Bulk Desktop App
Drag & drop up to 500 images → process all → get clean images in output folder.

✅ Features

🎯 Removes SynthID from Gemini, Imagen 2 & 3
🖥️ 100% browser-based — your images stay private
📦 Bulk processing (500+ images)
🔧 npm package for developers
⚡ Under 3 seconds per image
🆓 Free & open-source
📊 Supported Models
Model   Supported

Google Gemini   ✅
Imagen 2 & 3    ✅
DALL-E 3    ❌ (different method)
Midjourney  ➖ (no watermark)

🛠️ Tech Stack

Frontend: Next.js 14 + Framer Motion
Engine: JavaScript + Canvas API
Package: removebanana on npm
Hosting: Vercel

🔗 Links
🌐 Web App: removebanana.eu.cc
📦 npm: npm install removebanana
🛒 Bulk Service: Fiverr

Built this as a side project because I got tired of AI watermarks on my own generated images. Would love feedback — drop a comment! 🍌

DEV Community: Denuwan Lahiru

I Built a Free Tool to Remove Invisible AI Watermarks from Google Gemini Images

🔬 How It Works

⚡ 3 Ways to Use It

1. Web App (No Install)

2. npm Package