About this tool

Why it exists

Every other watermark remover asks you to upload first. That is a strange trade for a job that is, for still images, a few lines of arithmetic. Your file goes to a stranger's server, sits in a queue, and you get a result back with no way to know what happened to the original.

This page does the same job in the tab you already have open. The file is read from disk into memory, processed, and handed back. There is no upload step because there is nothing on the other end to upload to.

How reverse alpha blending works

Gemini does not burn its mark into the picture. It composites the mark on top using alpha blending, the standard way graphics software layers a semi-transparent image over another:

The logo and its per-pixel alpha map are both known quantities. That leaves one unknown in the equation, and it happens to be the pixel you want back. Rearranging gives:

This is an inverse, not an estimate, and it has consequences that matter in practice:

• Nothing is invented. Texture, grain and edges that sat under the mark come back as they were, rather than being repainted by a model that never saw them.
• The same file always gives the same result. There is no sampling, no seed and no temperature.
• It is fast. A still image finishes in roughly the time the browser needs to decode it.
• It fails honestly. Where the arithmetic cannot be trusted, the tool says so instead of quietly damaging the corner.

Finding the mark before removing it

The maths only works if the mark is exactly where the tool thinks it is. Detection runs in three layers: the image dimensions are matched against a catalogue of known Gemini output sizes, the predicted position is refined by searching for the logo anchor nearby, and the candidate removal is scored against the surrounding pixels before it is accepted.

If no layer produces a confident match, your file comes back untouched with a note. That is the intended behaviour. A watermark remover that alters images it does not understand is worse than one that declines.

Video

A video watermark is the same alpha blend repeated across every frame, with one complication: the codec has already smeared the edges of the mark by the time the file reaches you.

The video tool samples frames from across the clip to fix the mark's size and position once, then decodes every frame through WebCodecs, applies the same reverse solve inside the watermark footprint, and re-encodes an MP4. A small denoise model, 2.7 MB, served from this site and run locally, cleans the compression ringing that the arithmetic alone cannot reach. Your audio track is copied across without being re-encoded.

Because frames are decoded and encoded on your own machine, video needs a browser with WebCodecs H.264 encoding, which today means Chrome or Edge.

What it is built from

• The removal engine is the open source project by GargantuaX, MIT licensed, bundled here unmodified.
• Images run in a Web Worker so a large batch never freezes the page.
• Video runs through WebCodecs and Mediabunny for demuxing, decoding and muxing the result back into MP4.
• A service worker caches the page and its code, so the tool keeps working with no connection once you have loaded it.

What it handles

• Images. PNG, JPEG and WebP up to 50 MB each, in batches, returned as PNG. JPEG inputs can leave slightly more residue in the mark region, because the compression happened before you got the file.
• Video. MP4, WebM and MOV up to 500 MB, returned as MP4.
• Marks. The 48 px and 96 px Gemini sparkle and the scaled sizes between them, the newer light and dark outline variants, the Veo text mark, and marks that sit inset from the corner.

Who makes this

The site is built and maintained by Ravi Prajapati, who also writes the guides. It is an independent project rather than a company, and it is not affiliated with Google, Gemini, Veo or NotebookLM.

It began as a practical problem. The removal itself is a few lines of arithmetic for a still image, and every tool that did it wanted the file uploaded to a server first. That trade made no sense for a job that a browser can do on its own, so this does it in the tab instead.

The changelog records what has changed and when, and the guides document the measurements behind the decisions rather than just the conclusions. If something is wrong or a file will not clean, the contact page reaches a person.

A note on what you do with it

The watermark is a provenance signal. It exists so people can tell that a picture came out of a generative model. Taking it off your own work to use it cleanly is one thing. Taking it off to pass generated media off as something it is not is another, and that part is your call and your responsibility. The terms cover this in plainer legal language.