Automatically removes visible watermarks from Google Gemini AI-generated images. Available as a Tampermonkey userscript and a Chrome/Firefox extension. Zero-click — just install and forget.
| Before | After |
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Gemini stamps a semi-transparent white 4-pointed star logo in the bottom-right corner of every generated image using alpha compositing:
watermarked_pixel = alpha * 255 + (1 - alpha) * original_pixel
ClearGem reverses this mathematically to reconstruct the original pixels:
original_pixel = (watermarked_pixel - alpha * 255) / (1 - alpha)
Pre-calibrated alpha maps (48x48 and 96x96) are embedded directly. No AI inpainting, no server calls, no quality loss — pixel-perfect reconstruction with 99.9% accuracy (bounded only by 8-bit quantization).
- Zero-click — images are cleaned automatically as they appear in chat
- Download interception — Gemini's download button delivers clean images
- Copy interception — Gemini's copy button copies clean images to clipboard
- Auto-detection — picks 48x48 or 96x96 watermark size based on image dimensions
- Corner auto-detect — scans all four corners to find the watermark, handles edge cases where Gemini places it in non-default positions
- Multi-site support — works on Gemini, AI Studio, Vertex AI, and Google Labs
- 100% client-side — nothing leaves your browser
- Toast notifications — subtle Shadow DOM-isolated confirmation when images are cleaned
- Install Tampermonkey (or any userscript manager)
- Download
cleargem.user.jsfrom the latest release — Tampermonkey will prompt to install - Navigate to gemini.google.com — active immediately
- Download
ClearGem-v1.1.0.zipfrom the latest release and unzip - Go to
chrome://extensions, enable Developer mode - Click Load unpacked and select the unzipped folder
Or drag the .crx file onto the extensions page.
- Download
ClearGem-v1.1.0.xpifrom the latest release - Go to
about:addons, click the gear icon, select Install Add-on From File
| Site | Userscript | Extension |
|---|---|---|
| gemini.google.com | Yes | Yes |
| aistudio.google.com | Yes | Yes |
| console.cloud.google.com (Vertex AI) | Yes | Yes |
| labs.google | Yes | Yes |
| imagegeneration.vertex.ai | Yes | Yes |
Userscript works with Tampermonkey MV3 (@inject-into content). Extension is Manifest V3.
- Removes the visible watermark only. Does not remove SynthID — Google's invisible steganographic watermark embedded at the pixel generation level. That requires diffusion model re-processing and is a fundamentally different problem.
- If Google changes the watermark pattern, position, or alpha values, the embedded alpha maps will need updating.
Reverse alpha blending method and calibrated watermark masks based on GeminiWatermarkTool by Allen Kuo (MIT License). Alpha map data sourced from gemini-watermark-remover.
MIT