Gemini Watermark Remover
Remove the visible Gemini sparkle watermark from images you generated, with exact reverse alpha blending instead of AI guesswork. Runs entirely in your browser, so your image is never uploaded.
Quick answer:To remove the visible Gemini sparkle watermark, drop the original full-size image into the tool, check the before and after preview, and download the PNG. It uses reverse alpha blending in your browser, removes only the visible mark (not the invisible SynthID), and works on unedited Gemini downloads only.
Azam Sharieff· Finance & Tools Reviewer
Last reviewed:
How the removal works
Gemini draws a semi-transparent white sparkle in the bottom-right corner of generated images. Because the same mask is used every time, the blend can be reversed with arithmetic: the original pixel equals the watermarked pixel minus the watermark's contribution, divided by one minus its opacity. This is called reverse alpha blending. It recovers the underlying pixels rather than painting over them with a guess, so the surrounding picture is left untouched.
The engine is the open-source gemini-watermark-remover project by GargantuaX, released under the MIT licence (licence text). ToolsDock runs it in your browser; credit for the technique belongs to its authors.
What it can and cannot do
It works best on unedited, full-size images downloaded straight from Gemini. If an image has been cropped, resized, recompressed by a messaging app or screenshotted, the watermark no longer sits where the tool expects and it may report that nothing was found. In that case the image is returned unchanged, so you lose nothing by trying.
It removes only the visible sparkle. It does not and cannot remove SynthID, the invisible watermark Google embeds in AI-generated content, which is designed to survive edits. Other tools such as the Image Cropper and Image Resizer are better suited to general edits.
Use it responsibly
This tool is meant for images you generated yourself, for example to use a clean picture in a design or presentation. Removing the visible mark does not change the fact that the image is AI-generated. Do not present AI images as real photographs, and follow the terms of the service you generated them with and any disclosure rules that apply to your use, such as platform labels for AI content.
Your image is processed locally in your browser using canvas pixel data. Nothing is sent to ToolsDock's servers. After removal, compress the file with the Image Compressor if you need a smaller size, or switch format with PNG to JPG or JPG to WebP.
Working with Gemini videos too
Generated a clip as well as images? The Gemini Video Watermark Remover handles the visible Gemini and Veo mark in MP4 videos the same way: locally, in your browser, with no upload.