ChatGPT Checker — Detect ChatGPT Text Free
Paste at least 50 words to see how likely the text is to be written by ChatGPT or another AI model. Free for 10 checks a day, no account needed. For the sentences that look most AI-like, open the full detector. A score is a signal, not proof, so read the text yourself before deciding anything.
No login required
AI Models We Detect
Our detection engine is continuously updated to cover new and evolving language models — not just ChatGPT.
How ChatGPT Text Differs from Human Writing
Three key signals our models use to distinguish ChatGPT output from authentic human writing.
Low Perplexity
ChatGPT produces text with consistently low perplexity — meaning each word choice is highly predictable given the preceding context. Human writing is far more varied.
Low Burstiness
Human writers alternate between short and long sentences unpredictably. ChatGPT outputs show low burstiness — sentences cluster at similar lengths.
Predictable Structure
AI-generated text follows formulaic paragraph structure and transition patterns. Our models are trained to identify these structural fingerprints.
Who Uses ChatGPT Detection?
From classrooms to newsrooms, anyone who needs to verify authentic human writing relies on ProofAI.
Students verifying their own work
Check your own writing before submission to understand how it scores against AI detection systems.
Educators checking submissions
Quickly flag assignments and essays that may have been generated or heavily assisted by AI tools.
Publishers verifying content
Ensure articles, blog posts, and editorial content meet human-authorship standards before publication.
HR teams reviewing applications
Detect AI-generated cover letters and application responses to ensure authentic candidate communication.
What Happens to Your Text
Your text and files are used only to produce your result and are not saved by ProofAI. To analyse them we send them to AI model providers listed in our privacy policy. We keep a record of each check (date, type and score, not your content); signed-in users see it in their history. No account is required.
Wrongly flagged as ChatGPT? What to do
False positives happen, especially with short or formal writing and with writers whose first language is not English. If your own work is flagged, stay calm and gather evidence of your process: earlier drafts, notes, document version history (Google Docs and Word both keep it), browser history of your research and any sources you used.
Offer to explain your argument or rewrite a paragraph live. Ask which tool and score were used, and point out that detector results are probabilities that the tool makers themselves say should not be used as sole proof.
How to identify ChatGPT text
ChatGPT writes by predicting likely next words, so its text tends to be fluent, balanced and evenly paced. That is exactly what a ChatGPT detector measures. When you read text yourself, a few patterns are common in unedited ChatGPT output:
- Openers and closers like “In today’s fast-paced world…”, “It’s important to note…”, “Overall,” or “In conclusion,”.
- Lists of three (“clear, concise and compelling”) and neatly parallel sentences.
- Confident, general statements without specific names, numbers, dates or personal experience.
- Very even sentence length and tone from start to finish.
- Headings and bullet points in places where a person would normally write a paragraph.
ChatGPT checker vs reading it yourself
| Reading manually | ProofAI ChatGPT checker | |
|---|---|---|
| Speed | Minutes per document | Seconds |
| Consistency | Depends on the reviewer | Same analysis every time |
| Edited ChatGPT text | Hard to spot | Mixed scores and highlighted passages show where to look |
| Context and intent | A person understands the assignment or brief | Cannot judge context; use your judgement |
| Best use | Final decision | Deciding which texts need a closer look |
Not just ChatGPT
Text from Gemini, Claude, Llama-based tools and AI writing assistants shares many of the same statistical patterns, so the checker is useful beyond ChatGPT. For sentence-level highlights use the AI text detector; for PDF and Word files use the AI checker for PDF and Word.
How to check if text was written by ChatGPT
Paste the text
Copy at least 50 words into the ChatGPT checker at the top of this page. The whole piece gives a better result than a single paragraph.
Run the check
Click Check for AI. You get an AI probability and a human probability in seconds, with no login for your first scans.
Look for flagged passages
For a sentence-by-sentence view, open the AI text detector. Red sentences read most like ChatGPT output.
Confirm with context
Compare with the writer’s other work, ask about their process and check facts and sources, which ChatGPT sometimes invents.
Can rewritten ChatGPT text still be detected?
Paraphrasing tools, “AI humanizers” and manual editing can all change the statistical patterns that detectors rely on, so heavily rewritten ChatGPT text is harder to detect. At the same time, rewriting often leaves its own traces: uneven quality, odd synonyms and passages that still read as AI while others do not. Mixed or borderline scores are therefore a reason to look more closely, not a sign that the text is definitely human.
No detector can catch every edited AI text, and none can prove authorship on its own. The most reliable approach combines a detector score with context: drafts, version history, the writer’s usual style and a conversation about the work.
When people check for ChatGPT writing
Teachers
Before grading essays and homework. See the AI essay checker.
Students
Before submitting, to make sure their own writing is not mistaken for AI.
Recruiters
When reading cover letters and written test answers. See the AI resume detector.
Editors and clients
When reviewing freelance articles, blog posts and marketing copy.
Can Turnitin detect ChatGPT? And which checker is free?
Turnitin offers AI writing detection, including for ChatGPT-style text, but only to schools and universities that license it; students and individuals cannot buy it directly, and instructors see the result. If you are a student or an individual who wants to check text yourself, you need a separately available checker. See our ProofAI vs Turnitin comparison.
ProofAI’s ChatGPT checker is free to start: 10 checks per day without an account and 25 per day with a free account, with paid plans in INR for higher volumes. Whichever checker you use, remember that different tools can give different scores for the same text, because each uses its own models and thresholds.
From the blog
All articles
AI Detector False Positives: Why Human Writing Gets Flagged
AI detectors sometimes flag human writing. What the research says about false positives, who is most at risk, and what writers and reviewers can do.
How to Spot AI-Generated Fake Reviews Before You Buy
Practical signs of AI-written fake reviews, what India's IS 19000:2022 and the US FTC rule say, and how shoppers and sellers can respond.
Signs Content Was Written by ChatGPT (and Their Limits)
Practical signs that text may be ChatGPT-written, how to check them, and why no single sign or detector score proves authorship.
Frequently Asked Questions
Yes. ProofAI is trained to detect text patterns produced by ChatGPT, GPT-4, GPT-4o, and other OpenAI models. It also detects content from Gemini, Claude, Llama, and other major language models.
Yes. You can check for ChatGPT-generated text for free without creating an account. Visit our AI Detection Hub to start scanning immediately.
Our system analyzes linguistic properties like perplexity, burstiness, sentence predictability, and vocabulary distribution — characteristics that differ measurably between human and ChatGPT-generated writing.
Yes. Our advanced models detect structural and statistical patterns that remain even after light paraphrasing. However, heavily rewritten content may score lower — no detector is 100% perfect on all variations.
Yes. 10 checks a day without an account, 25 with a free account.
At least 50. A full essay or article gives a more reliable result than one paragraph.
It detects text from all major models, but it gives one AI-likelihood score rather than naming the model.
Your text and files are used only to produce your result and are not saved by ProofAI. To analyse them we send them to AI model providers listed in our privacy policy. We keep a record of each check (date, type and score, not your content); signed-in users see it in their history. ProofAI does not use your text to train its own models.
Is It ChatGPT? Find Out Instantly.
Free ChatGPT text detection with no login and a sentence-level breakdown. Your text is not saved. Start scanning now.