Watermark · detector · humanizer

Markdown

A watermark is a mark the model left. A detector is someone else’s guess.

A text watermark is a signal the generating model put in the words, using a key the provider holds. An “AI detector” or “humanizer” score is a separate guess about how typical the prose looks. Those tools do not hold ChatGPT, Claude or Gemini keys. Gifi inspects hidden characters, rewrites a statistical trail, or strips file metadata. It is not a detector API, and it will not sell a bypass of GPTZero or Originality.

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Process

How to verify the job

  1. 01

    Ask which question you have

    “Did this lab mark the words?” is a watermark question. “Does this website think the prose looks like a model?” is a detector question. They are not the same job.

  2. 02

    Inspect what can be named

    Paste the text. Invisible Unicode is real and deletable. A detector score will not appear there, and a statistical watermark will not either.

  3. 03

    Refuse the wrong product

    If you need a lab’s detector, use that lab. If you need different words, that is a rewrite. Gifi will not certify either outcome against a private key.

Scope

Supported and unsupported surfaces

SurfaceGifi actionVerification limit
Named metadata or invisible UnicodeInspect, remove, and report named actionsReinspect the returned bytes independently
Statistical patterns in ordinary wordsRewrite the proseNo certificate against a private detector
Visible logos, pixels, audio, or videoUnsupportedNo removal claim

Two different objects

SynthID-Text and Claude’s published mark are generative watermarks. The model biased its next-word choice. A later reader who holds the same key can test for that bias. No key, no test. The sentence does not need hidden characters.

Classifier “AI scores” look at style: burstiness, favourite phrases, how predictable the next word seems. They can fire on human text and miss marked text. They are not reading Anthropic’s key or Google’s key.

Why humanizers talk past the mark

A page that promises to “remove the ChatGPT watermark” and then sells a style rewrite is usually selling a detector score. ChatGPT does not watermark text today. Claude and Gemini do. Mixing those sentences is how the category stays confused.

Gifi will change the words when the concern is a statistical trail. It will not promise that GPTZero, Originality, or any other classifier will move. That would be a different, false product.

What Gifi is, and is not

The API can inspect, clean and rewrite. Inspect reports named characters and a style heuristic. The heuristic is not a watermark detector. The rewrite is not a certificate.

If a vendor later publishes a detector, we may attach a best-effort score to a rewrite. That score will still not be a certificate. The key remains theirs.

Questions this usually raises

Is Gifi an AI detector?
No. The paste box names hidden characters and a writing-style heuristic. It does not hold a lab key.
Will a rewrite make GPTZero say the text is human?
We do not know, and we will not sell that outcome. A classifier is not a watermark.
Then what is the point of a rewrite?
To choose different words, which is the only honest lever against a keyed word-choice mark. The prose will change. That is all we can say.