gemini-watermark-remover README

The project's README from github.com/GargantuaX/gemini-watermark-remover. As one markdown file: README.md.

中文文档

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Gemini Watermark Remover — Lossless Watermark Removal Tool

An open-source tool to remove Gemini watermarks from AI-generated images with high-fidelity, reproducible results on supported outputs. Built with pure JavaScript, the engine uses a mathematically exact Reverse Alpha Blending algorithm instead of unpredictable AI inpainting.

🚀 Looking for the Online Gemini Watermark Remover (Recommended)? Try geminiwatermarkremover.io — free, no install, works directly in your browser.

💡 Got watermarks that Gemini Watermark Remover can't handle? Try the general-purpose AI watermark remover: pilio.ai/image-watermark-remover

Online Tool  Video Watermark Remover  Chrome Extension  Userscript  General Watermark Remover

Features

Gemini Watermark Removal Examples

Click to Expand/Collapse Examples
Original Image Watermark Removed

⚠️ Disclaimer

[!WARNING] USE AT YOUR OWN RISK

This tool modifies image files. While it is designed to work reliably, unexpected results may occur due to:

  • Variations in Gemini's watermark implementation
  • Corrupted or unusual image formats
  • Edge cases not covered by testing

The author assumes no responsibility for any data loss, image corruption, or unintended modifications. By using this tool, you acknowledge that you understand these risks.

[!NOTE] Note: Disable any fingerprint defender extensions (e.g., Canvas Fingerprint Defender) to avoid processing errors. https://github.com/GargantuaX/gemini-watermark-remover/issues/3

How to Remove Gemini Watermarks

For all users — the fastest and easiest way to remove Gemini watermarks from images:

  1. Open geminiwatermarkremover.io.
  2. Drag and drop or click to select your Gemini-generated image.
  3. The engine will automatically process and remove the watermark.
  4. Download the cleaned image.

Online Video Watermark Remover (New!)

For Gemini-generated videos with visible watermarks:

  1. Open geminiwatermarkremover.io/video.
  2. Upload or drag-and-drop your Gemini-generated video.
  3. The tool will automatically detect and remove the watermark from the video.
  4. Download the cleaned video.

Note: Video watermark removal runs entirely in your browser — no files are uploaded to any server.

Chrome Extension

Use this if you do not want a userscript manager but still want automatic Gemini page integration for previews, copy, and download actions.

  1. Open Gemini Watermark Remover on the Chrome Web Store.
  2. Click Add to Chrome and confirm the install.
  3. Open Gemini. The extension will automatically process supported Gemini images.

The popup includes an "Enable on Gemini" toggle. If Gemini becomes slow, behaves unexpectedly, or you need to troubleshoot the page, turn the toggle off and refresh Gemini.

Chrome Web Store installs update automatically. If the Web Store is not reachable in your network, the matching verified zip (gemini-watermark-remover-extension-v*.zip) remains available from GitHub Releases and the official website download entry for manual unpacked installation.

Userscript

  1. Install a userscript manager (e.g., Tampermonkey or Greasemonkey).
  2. Open gemini-watermark-remover.user.js.
  3. The script will install automatically.
  4. Navigate to Gemini conversation pages.
  5. Eligible Gemini preview images on the page are replaced in place after processing.
  6. Gemini's native "Copy Image" and "Download Image" actions also return processed results.

Current userscript boundaries:

Skill

For workflows that involve AI coding agents:

pnpm dlx skills add GargantuaX/gemini-watermark-remover --skill gemini-watermark-remover

node skills/gemini-watermark-remover/scripts/run.mjs remove <input> --output <file>

CLI

For scripting, CI, and local batch workflows, use the direct CLI:

# repo-local
node bin/gwr.mjs remove <input> --output <file>

# installed globally
gwr remove <input> [--output <file> | --out-dir <dir>] [--overwrite] [--json]

Video exports default to the repository's calibrated 12 Mbps AVC profile. For a quality-sensitive source, request a higher encoder target explicitly:

gwr remove input.mp4 --output clean.mp4 --video-bitrate-mbps 20

The CLI reports video frame progress on stderr. --video-timeout-ms is an inactivity timeout: an export may run longer than that value as long as frames continue to advance.

If you do not have gwr installed globally, use:

pnpm dlx @pilio/gemini-watermark-remover remove <input> --output <file>

The default CLI file decoder/encoder uses sharp. SDK consumers that only use browser or ImageData APIs do not need it. If you use the CLI file path in your own project, install sharp alongside this package:

pnpm add sharp

Can't Remove Your Watermark?

This tool targets Gemini's visible watermark (the semi-transparent logo in the bottom-right corner). If your image watermark doesn't match a known Gemini format, or you need to remove other types of image watermarks, try the general-purpose AI watermark remover:

👉 pilio.ai/image-watermark-remover

Developer Preview

The repository still keeps a local internal preview harness at /dev-preview.html for single-image comparison, copy, and download verification.

Development

# Install dependencies
pnpm install

# Development build
pnpm dev

# Production build
pnpm build

# Local static serving
pnpm serve

Notes:

Tampermonkey Debugging on macOS

For the repo's fixed-profile workflow on macOS:

# Build the latest userscript
pnpm build

# Start a local dist server if needed
pnpm dev

# Open the fixed Chrome profile with remote debugging enabled
./scripts/open-fixed-chrome-profile.sh --url https://gemini.google.com/app

Notes:

SDK Usage (Advanced / Internal)

The package root still exposes an SDK, but this path is intended for advanced or internal integration scenarios:

import {
  createWatermarkEngine,
  removeWatermarkFromImage,
  removeWatermarkFromImageData,
  removeWatermarkFromImageDataSync,
} from '@pilio/gemini-watermark-remover';

Use the pure-data API when you already have decoded ImageData:

const result = await removeWatermarkFromImageData(imageData, {
  adaptiveMode: 'auto',
});

console.log(result.meta.decisionTier);

Use the browser image API when you have an HTMLImageElement or HTMLCanvasElement:

const { canvas, meta } = await removeWatermarkFromImage(imageElement);
document.body.append(canvas);
console.log(meta.applied, meta.decisionTier);

If you need to process many images, reuse a single engine instance so alpha maps stay cached:

const engine = await createWatermarkEngine();
const first = await removeWatermarkFromImageData(imageDataA, { engine });
const second = await removeWatermarkFromImageData(imageDataB, { engine });

For Node.js integrations, use the dedicated subpath and inject your own decoder/encoder:

import { removeWatermarkFromBuffer } from '@pilio/gemini-watermark-remover/node';

const result = await removeWatermarkFromBuffer(inputBuffer, {
  mimeType: 'image/png',
  decodeImageData: yourDecodeFn,
  encodeImageData: yourEncodeFn,
});

Runtime Requirements

Web And Userscript

CLI And Skill

node bin/gwr.mjs remove <input> --output <file>
node skills/gemini-watermark-remover/scripts/run.mjs remove <input> --output <file>

Testing

# Run all tests
pnpm test

Regression tests include image fixtures from src/assets/samples/. Source samples stay in git. Naming and retention rules for those fixtures are documented in src/assets/samples/README.md. Complex preview/download validation notes are documented in docs/complex-figure-verification-checklist.md. Local files under src/assets/samples/fix/ are optional snapshot outputs for manual regression checks and are intentionally not tracked by git.

Release Notes

See CHANGELOG.md for release history and RELEASE.md for the local release checklist. The latest post-release closeout is documented in docs/release-1.0.29-post-release.md.

How Gemini Watermark Removal Works

The Gemini Watermarking Process

Gemini applies watermarks using standard alpha compositing:

$$watermarked = \alpha \cdot logo + (1 - \alpha) \cdot original$$

Where:

The Reverse Solution

To remove the watermark, we solve for original:

$$original = \frac{watermarked - \alpha \cdot logo}{1 - \alpha}$$

By capturing the watermark on a known solid background, we reconstruct the exact Alpha map and apply the inverse formula to restore the original pixels with zero loss.

Detection Rules

The engine uses layered detection to locate and verify watermarks:

  1. Size catalog lookup — matches image dimensions against Gemini's known output sizes to predict watermark size and position.
  2. Local anchor search — refines the predicted position by scanning pixel data around the expected watermark region.
  3. Restoration validation — confirms the detected watermark is real before applying removal, avoiding false positives.

Default watermark configurations:

Condition Watermark Size Right Margin Bottom Margin
Larger Gemini outputs 96×96 64px 64px
Smaller Gemini outputs 48×48 32px 32px

Project Structure

gemini-watermark-remover/
├── bin/                   # Published CLI entrypoint (`gwr`)
├── public/
│   ├── index.html         # Entry page for official site / userscript / internal preview
│   ├── dev-preview.html   # Internal browser preview harness kept for local debugging
│   └── tampermonkey-worker-probe.*  # Probe pages for userscript/debug flows
├── skills/
│   └── gemini-watermark-remover/    # Distributable agent skill bundle
├── src/
│   ├── assets/            # Calibration assets and regression samples
│   ├── cli/               # CLI argument parsing and file workflows
│   ├── core/              # Watermark math, scoring, and restoration
│   ├── page/              # Page-side runtime for Gemini page integration
│   ├── sdk/               # Advanced/internal SDK surface
│   ├── shared/            # Shared DOM, blob, and session helpers
│   ├── userscript/        # Userscript entrypoints and browser hooks
│   ├── workers/           # Worker runtime
│   ├── app.js             # Internal single-image preview harness entry point
│   └── utils.js           # Shared browser helpers for the internal preview page
├── tests/                 # Unit, regression, packaging, and smoke tests
├── scripts/               # Local automation and debug launchers
├── dist/                  # Build output directory
├── build.js               # Build script
└── package.json

Architecture Overview

Limitations

This project is released under the MIT License.

The removal of watermarks may have legal implications depending on your jurisdiction and the intended use of the images. Users are solely responsible for ensuring their use of this tool complies with applicable laws, terms of service, and intellectual property rights.

The author does not condone or encourage the misuse of this tool for copyright infringement, misrepresentation, or any other unlawful purposes.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES, OR OTHER LIABILITY ARISING FROM THE USE OF THIS SOFTWARE.

Credits

This project is a JavaScript port of the Gemini Watermark Tool by Allen Kuo (@allenk).

The Reverse Alpha Blending method and calibrated watermark masks are based on the original work © 2024 AllenK (Kwyshell), licensed under MIT License.

License

MIT License

gemini-watermark-remover (GargantuaX/gemini-watermark-remover)

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5.7K ·GitHub
Gemini-watermark-remover
What is this?An open-source tool that removes Gemini AI watermarks from images (and videos) using a mathematically exact Reverse Alpha Blending algorithm instead of AI inpainting, available as an online tool, Chrome extension, userscript, CLI, and SDK.
Is this one app or several different tools?It ships as multiple interfaces around the same engine: a web app, a Chrome extension, a Tampermonkey userscript, a command-line tool (gwr), an agent Skill, and a JavaScript SDK.
How do I actually remove a watermark?Easiest way is opening geminiwatermarkremover.io and dragging in your Gemini image (or using /video for videos); for in-page automation on Gemini itself, install the Chrome extension from the Chrome Web Store or add the userscript via Tampermonkey.
Do I need anything installed to use the CLI?The CLI needs a local Node.js runtime, and its default file decoder/encoder depends on the sharp package, which you install alongside the package if you use the CLI file path; browser/SDK consumers using ImageData APIs don't need it.
Will it remove every watermark on my image?No - it only targets Gemini's current visible bottom-right logo watermark, not invisible or steganographic marks like SynthID, and only works reliably on outputs matching Gemini's known size catalog.
Which browsers does it support?The web tool and userscript work in modern Chrome, Firefox, Safari, and Edge, while the CLI and SDK run in Node.js environments.
Does my image get uploaded anywhere?No, all processing - including video - happens locally in your browser or on your machine, and nothing is sent to a server.
How does the watermark removal actually work?It reverses Gemini's alpha-compositing formula: by capturing the known watermark logo on a solid background it reconstructs the exact alpha map, then solves for the original pixel value, recovering the image with zero loss instead of guessing with AI inpainting.
Does it also work on Gemini-generated videos?Yes, the online tool has a dedicated video mode at geminiwatermarkremover.io/video that detects and removes the watermark frame-by-frame, running entirely in the browser.
What is the included Skill for AI coding agents?It's a packaged Skill under skills/gemini-watermark-remover/ that agents can discover and invoke via skills.sh, wrapping the CLI boundary so agents can automate watermark removal without importing repo internals.
Can it remove watermarks from other AI tools, not just Gemini?No, it's built specifically to detect Gemini's bottom-right logo watermark; for other watermark types the README points to the separate general-purpose pilio.ai/image-watermark-remover.
What are similar projects?remove-ai-watermarks, JHS-enhance, maxurl, video_vip, return-youtube-dislike, FluentRead, sentrysearch, Telegram-Media-Downloader
Which topics is it in?client-side, userscript, image, chrome-extension, video-processing, browser-extension, image-processing, video, skills, gemini, sdk, privacy
Creator
GargantuaX
Size
441.7 MB
Stars
5.7K
Updated
CommitOct 04Releasev1.0.46Oct 02
Age
9mo
Commits · 90 Days