NOT THIS
A plagiarism checker
Plagiarism tools ask whether your writing resembles something that already exists. That needs a library of other people’s documents. We do not hold one and we do not compare your work to anyone else’s.
This is the page we would want to read if we were buying this. What we can actually do when you send us a document today, what we cannot, and the three things people keep expecting us to be.
Read the third column first. It is the one most sites in this market do not print.
| Signal | What it would tell you | Where we stand today |
|---|---|---|
| Content Credentials (C2PA) | A signed record attached to the file saying how it was made and by what. | Working. We read these on PDFs and on text, check the signature against the official trust list, and reject a file where one character has changed. |
| Google SynthID | A hidden marker some AI systems place in text they generate. | Partly. We can detect it where the keys are known to us, which is how we test and calibrate. We cannot read Google’s production watermark, because that needs Google’s own detector. |
| Claude’s text watermark | The same idea, for text written by Anthropic’s models. | Not yet. Detection is in private preview and we have not been granted access, so we cannot detect it today. The code is written and waiting. We will say so here the day that changes. |
| Statistical detectors | A guess, from the writing style, about whether AI was involved. | Supported, deliberately limited. You can connect one you already pay for. We measure how often it is wrong and weight it accordingly. It can never produce an accusation on its own. |
If that looks like a short list, it is. A watermark only exists if whoever made the content chose to put one there, and most of the world has not started yet. The useful product is the one that is straight with you about that.
Plagiarism tools ask whether your writing resembles something that already exists. That needs a library of other people’s documents. We do not hold one and we do not compare your work to anyone else’s.
We do not produce a percentage of matched text. If that is what you need, you need a plagiarism tool, and we will tell you so.
Those score how AI-sounding your prose is. Independent testing puts them well below their advertised accuracy, and they misfire hardest on people writing in a second language. We read evidence the document actually carries. Where we do use a detector, we cap how much it counts.
Because the alternative is that you find out later, and because a verification company that oversells its own coverage has destroyed the only thing it was selling. If a check starts working, this page changes and the date changes with it. If one stops working, the same.