Gemini Watermark Remover
Upload an image generated by Google Gemini (sometimes called “Nano Banana”) and this tool mathematically reverses the small, semi-transparent logo watermark Gemini stamps in the corner - no AI guessing, no upload to a server, just exact pixel math running in your browser.
Drag & drop an image, or click to browse
PNG, JPG or WEBP - a Gemini / Nano Banana AI image
How this actually works
Gemini composites its watermark logo onto an image using standard alpha blending: watermarked = alpha × logo + (1 - alpha) × original. Because Gemini always renders that badge at the same handful of output resolutions with a consistent, measurable opacity per pixel, the blend can be solved exactly in reverse: original = (watermarked - alpha × logo) / (1 - alpha). This is called Reverse Alpha Blending - deterministic per-pixel arithmetic, not an AI model and not inpainting, so it's instant and never invents pixels that weren't already implied by the math.
The calibrated opacity masks and known Gemini output sizes this tool uses are adapted, under the MIT License, from the open-source gemini-watermark-remover project (Copyright (c) 2025 Jad; Copyright (c) 2024 AllenK). That project's own documentation credits the underlying Reverse Alpha Blending method and calibrated watermark masks to the original work by AllenK. This tool ports only that deterministic pixel-math core - not its ML denoiser or video watermark removal - to keep everything client-side and free to run.
Questions fréquentes
Does this use AI to remove the watermark?
No. It uses Reverse Alpha Blending, a deterministic pixel-math formula that exactly inverts how Gemini composited the watermark in the first place. There's no machine-learning model involved and nothing is uploaded to a server - the math runs entirely in your browser.
Which images does this work on?
It's built around Gemini's known official output resolutions (the 0.5K/1K/2K/4K image sizes across Gemini's supported aspect ratios), where the watermark's exact size, position and opacity are known. If your image matches one of those sizes exactly, the watermark box is placed automatically. For a resized, cropped, or screenshotted image, the tool falls back to Gemini's general sizing rule and lets you drag the highlighted box onto the logo yourself before removing it.
What if the auto-detected box doesn't line up with the logo?
Drag the highlighted box directly onto the watermark, use the arrow nudge buttons for pixel-precise placement, or switch the badge size between 48px and 96px (Gemini's two standard sizes) - then run the removal again.
Will this leave a visible ghost or dark smudge behind?
On an exact-resolution match it should be effectively invisible. On approximate or unusual images, the tool automatically checks whether the standard correction would clip too many pixels to black or white and softens it if so - you may see a faint trace in that case rather than a solid dark block. If a mark remains, try adjusting the box position for a cleaner fix.
Does it work on Gemini video watermarks?
No, this tool only handles static images (PNG, JPEG, WebP). Removing the Veo video watermark requires frame-by-frame video processing, which is out of scope for this free, browser-only tool.
Is my image uploaded anywhere?
No. Everything - loading the image, detecting the watermark position, and reversing the blend - happens locally in your browser using canvas. Nothing is sent to a server.