Copyleaks started as a plagiarism checker and now sells one of the more widely used AI content detectors, used by schools, publishers and businesses. If you write with ChatGPT, it is one of the tools your text may pass through.
Quick Answer
Yes. Copyleaks is built to detect ChatGPT, Claude, Gemini and other models, and it highlights which sentences look AI-written. Raw, unedited AI text is flagged most reliably. Text that has been restructured and rewritten in your own voice is much harder for it to call.
How Copyleaks Detects AI Text
Copyleaks analyzes a document with a model trained on large amounts of human and AI writing. It does not match phrases against a database. Instead it estimates how likely each part of the text is to have been produced by a language model, and shows the result as an overall percentage plus highlighted passages.
- Sentence-level highlighting — you can see exactly which passages triggered the score, not just a total.
- Multi-model coverage — it is designed to recognize output from several popular models, not only ChatGPT.
- Multilingual support — it covers many languages, unlike detectors that are strongest in English only.
What Copyleaks Claims vs What to Expect
The figures below are the vendor's positioning and general behavior, not our own test results.
Why Paraphrasing Tools Often Fall Short
Copyleaks says it looks for reworded AI text as well. In practice, tools that only swap words leave the underlying sentence structure and rhythm untouched, and that is what a detector reads. Changing the surface without changing the structure rarely moves the score much.
Usually not enough
- −Synonym swapping
- −Basic paraphrasers
- −Changing a few words per sentence
- −Re-prompting the same model
Helps more
- +Restructuring sentences
- +Mixing short and long sentences
- +Adding specific, personal detail
- +Humanizing, then proofreading
How to Reduce a Copyleaks AI Score
Check which sentences are highlighted
Copyleaks shows the flagged passages. Those are the parts to rework first.
Humanize the draft
Run the text through Fresh Text to rebuild sentence structure and rhythm rather than swap words.
Add what only you know
Concrete examples, sources and opinions are hard for a model to fake and make the text yours.
Re-check and proofread
Read the result for accuracy and tone. Follow the rules on AI use at your school or workplace.
Frequently Asked Questions
Does Copyleaks detect ChatGPT?▾
Yes. Copyleaks offers an AI content detector that is designed to flag text from ChatGPT and other large language models, and it reports results sentence by sentence.
How accurate is Copyleaks?▾
Copyleaks claims very high accuracy and a very low false positive rate. Independent results vary with text length, topic and how much the text was edited, so treat any single number with caution.
Does Copyleaks detect paraphrased AI text?▾
Copyleaks says its detector also looks for AI text that has been reworded. Simple synonym swaps are less likely to hide the pattern than a genuine rewrite of structure and rhythm.
Does Copyleaks work in other languages?▾
Yes. Copyleaks supports AI detection in many languages beyond English, which sets it apart from some competitors.
Can Copyleaks flag human writing as AI?▾
It can. Like every detector, it sometimes flags formal, formulaic or non-native writing. A flag is a signal to look closer, not proof.
Conclusion
Copyleaks does detect ChatGPT, and its sentence-level view makes it easy to see what triggered a flag. Raw AI text is caught most reliably; genuinely restructured text is much harder to classify. Use any tool to improve the writing, not to replace your own judgment.