Frequently asked questions

Is this tool guaranteed to work?

No — and we won't pretend otherwise. SynthID is built to be stubborn, and detectors keep changing. ClearMark breaks the watermark signal apart in the frequency domain, and results vary by file, format and detector. If the result matters to you, check it yourself with Google's free detector at synthid.com.

Does Gemini use SynthID to watermark images?

Yes. Gemini weaves SynthID-style invisible watermarks into generated images — signals hidden in the pixels themselves, not just metadata. That's why cropping or re-saving doesn't remove them, and why the fix has to work at the pixel level.

How does the cleaning work?

Your image is read in the frequency domain, where the watermark pattern lives. Small, targeted changes interfere with that pattern while the picture stays visually unchanged. Metadata — the C2PA record, EXIF data, all of it — is stripped out when the file is re-encoded. And everything happens in your browser.

Is my data uploaded to any server?

No. ClearMark works entirely inside your browser. We never upload your images, never store your files, and keep no copy after you download the cleaned version.

How can I tell if the watermark was removed?

You can't tell by looking — SynthID is invisible by design. The reliable way is Google's SynthID Detector at synthid.com (free, about 10 checks a day). Upload the original and the cleaned file, and compare the two results.

Will removing the watermark affect image quality?

It's designed not to. Resolution, colour, sharpness and contrast stay visually the same — and the tool shows you a PSNR quality score after each cleaning, so you can see the number for yourself. Keep the original file so you can compare.

What image formats are supported?

PNG, JPG and WebP. For best results, use the original exported file — before heavy compression or being re-saved over and over.

Does it support video?

Not yet. Video needs the same treatment on every single frame, which is much heavier work. It's on the roadmap — and when it lands, it'll be free too, inside the same daily limit.

Is watermark removal legal?

It depends on where you are, the platform's rules, and what you use it for. Use ClearMark only on content you own or have the rights to. Removing a watermark to misrepresent where content came from can break platform rules — that part is on you.

What is the difference between SynthID and C2PA?

C2PA is metadata — a signed record attached to the file, and re-exporting can remove it. SynthID is embedded in the pixels themselves, so it survives re-encoding. That's why ClearMark does both: strip the metadata and disrupt the pixel signal.

Do I need an account?

No. There is no sign-up, no email, no password. Your daily counter lives in this browser only — 10 cleanings a day, resetting at midnight.