Free Plagiarism Checker — Detect Copied & AI-Generated Content
Check your text for plagiarism and AI-generated content. Our plagiarism checker identifies copied passages and flags text that reads as machine-written.
Used by students and educators worldwide
Results vary by text type. Review output before use.
What Is a Plagiarism Checker?
A plagiarism checker compares your text against published sources to identify copied or closely paraphrased content. Traditional plagiarism checkers scan billions of web pages, academic papers, and published works to find matching passages. They report an originality percentage and highlight specific sentences that match existing sources.
In 2026, plagiarism checking has expanded beyond traditional copying. AI-generated content — text produced by ChatGPT, Claude, Gemini, and similar tools — is now the most common form of academic dishonesty. Modern plagiarism checkers must detect both traditional plagiarism (copying from sources) and AI plagiarism (submitting machine-generated text as your own work). Our tool addresses both.
Why Check for Plagiarism?
Originality matters — for grades, credibility, and legal protection.
Protect Academic Integrity
Universities use Turnitin and similar tools to check every submission. Running your work through a plagiarism checker first ensures you won't face academic misconduct charges for unintentional matches.
Detect AI-Generated Content
AI-generated text is now flagged by most academic and professional institutions. Our tool combines plagiarism checking with AI detection to catch both traditional copying and AI authorship.
Avoid Serious Consequences
Plagiarism consequences range from failing grades to expulsion in academia, and from reputation damage to legal liability in professional settings. A 30-second check prevents these outcomes.
Build Trust & Credibility
Original content builds your reputation. Whether you're publishing research, writing for clients, or creating blog content, verified originality demonstrates professionalism.
Plagiarism Checker Features
Comprehensive content originality analysis for the AI age.
Deep Content Scanning
Scans your text against billions of web pages, academic databases, and published works to identify matching content — even when paraphrased or slightly modified.
AI Content Detection
Identifies text generated by ChatGPT, Claude, Gemini, and other AI tools. Detects the statistical patterns that distinguish machine-written text from human writing.
Source Identification
When matches are found, we show you the original sources so you can properly cite them or rewrite the matching passages.
Instant Results
Get your plagiarism report in seconds. No file uploads, no waiting in queues — paste your text and get results immediately.
High Accuracy
Our detection algorithms minimize false positives. Common phrases and properly cited quotes are recognized and excluded from the plagiarism score.
Detailed Reports
Get a clear originality percentage, highlighted matching passages, and identified sources. Understand exactly what was flagged and why.
Plagiarism Checker Comparison
How our plagiarism checker compares to Turnitin and GPTZero.
| Feature | HumanizerAI | Turnitin | GPTZero |
|---|---|---|---|
| Plagiarism detection | |||
| AI content detection | |||
| AI humanization | |||
| Paraphrasing tool | |||
| Free tier available | |||
| No signup to try | |||
| Source highlighting | |||
| Percentage score |
Who Uses a Plagiarism Checker?
Educators & Professors
Check student submissions for copied content and AI-generated text. Our tool catches both traditional plagiarism and AI authorship, the two biggest academic integrity concerns in 2026.
Students
Run your own work through the plagiarism checker before submitting. Catch unintentional matches, verify your citations are properly formatted, and ensure your AI-assisted research is sufficiently paraphrased.
Publishers & Editors
Verify content originality before publication. Check freelancer submissions, guest posts, and staff articles for plagiarism and AI-generated content.
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Plagiarism Checker FAQ
How does the plagiarism checker work?
Our plagiarism checker analyzes your text in two ways: it compares your content against web pages and academic sources to find matching passages (traditional plagiarism), and it analyzes writing patterns to detect AI-generated content. You get a combined originality report covering both types of plagiarism.
Can it detect AI-generated content?
Yes. Our plagiarism checker includes AI detection that identifies text written by ChatGPT, Claude, Gemini, and other AI tools. This is increasingly important as universities and publishers now flag AI-generated submissions alongside traditional plagiarism.
Is this plagiarism checker free?
You can check your text for plagiarism for free. For detailed source reports and higher word limits, premium plans start at $7/month.
How is this different from Turnitin?
Turnitin is used by institutions and isn't available to individual students. Our plagiarism checker lets anyone check their work before submission. We also combine traditional plagiarism detection with AI content detection in one tool — Turnitin treats these as separate features.
Will my text be stored or shared?
No. Your text is processed in real-time and not stored in any database. We do not share your content with third parties or add it to any plagiarism database.
What percentage of plagiarism is acceptable?
There's no universal standard, but most institutions accept 10–15% similarity, which typically consists of common phrases and properly cited quotes. Anything above 20% usually warrants review. For AI detection, most institutions expect 0% AI-generated content in student submissions.
Check Your Content for Originality
Detect plagiarism and AI-generated content before your audience does. Try our full suite of AI writing tools.