AI Text Checker
These are signs, not proof: people write this way too, and an AI text that was edited may show none of them.
How to check a text for AI signs
AI Text Checker colours the ways of writing that chatbots leave behind and shows every character that does not appear when you read, in your browser, so the text never leaves your device.
- Paste the text
Paste a text into the box. The result shows as soon as you paste or edit.
- Read the colours
Each colour is one kind of sign. A hidden character shows as a purple box with its code; hover over it for its name.
- Copy the clean text
Press Copy clean text for the text without hidden characters and look-alike letters; tick the option to remove ** and # too.
Frequently asked questions
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Does it tell me whether AI wrote the text?
No. It marks ways of writing that are common in chatbot text, and gives no percentage. Nothing can prove who wrote a passage: people write this way too, and an AI text that was edited may show no sign at all. Do not use the result to judge someone else’s work.
What are hidden characters, and why are they in my text?
Characters that do not show when you read: zero-width spaces, narrow no-break spaces, text-direction marks, tag characters. They come along when text is copied from a web page, Word or a chatbot’s answer. They can stop a line from wrapping, stop a search from finding a word, or carry hidden words.
Does ChatGPT mark its text with hidden characters?
In April 2025 people found narrow no-break spaces (U+202F) in answers from some ChatGPT models. OpenAI said they were not a watermark, and they stopped appearing soon after. The tool still finds them, along with the other hidden characters.
If I remove hidden characters, can an AI detector still tell?
It may still. AI detectors read the wording and the rhythm of the sentences, not hidden characters. Removing them gives you a clean text to paste elsewhere: lines wrap, searches find words, and no hidden words travel with it.
What is hidden text in hidden characters?
Tag characters and runs of variation selectors can carry words you cannot see, such as a hidden instruction for a chatbot that reads the text. When the tool finds them, it decodes them and shows the words.
Is my text sent to a server?
No. Everything runs in your browser; the text is not sent anywhere.