Self-Plagiarism & AI Content Checker
Check your own text for self-plagiarism (repeated sentences), AI-generated writing patterns, and unusual phrase repetition — all in your browser. It does not scan the web or compare against online databases. No uploads, no server, 100% private.
What this tool can and cannot do: It detects self-plagiarism, AI writing patterns, and repeated phrases inside your document. It cannot check against Google, websites, or academic databases — that requires a server. All detections shown are from inside your document only. Use the Verify Online links to manually check suspicious sentences on Google Scholar.
How to Check Your Essay for Plagiarism Free
Upload or Paste
Upload .docx or .txt, or paste text. No character limits.
Real Analysis
Self-plagiarism detection, AI-pattern analysis via 7 statistical signals, and phrase repetition detection.
Verify Manually
Use the built-in Google / Scholar links to check suspicious sentences against the real internet.
Real situations where this self plagiarism checker helps
This checker works entirely inside your own document — it does not crawl the web. That sounds like a limitation, but it turns out to be exactly what you want in a lot of everyday situations. Here are the ones people actually use it for.
Catching accidental self-plagiarism before you submit
When you have been staring at the same essay for hours, it is easy to reuse a strong sentence twice without noticing, or to paste a paragraph you already wrote in the introduction back into the conclusion. Turnitin counts repeated blocks like that against you. Paste your finished essay here first and the Repeated Sentences panel shows every line that appears more than once, so you can rewrite or delete it before your professor ever sees it.
Checking a thesis chapter for repeated phrasing
Long documents drift into verbal tics. Across forty pages you might lean on the same five- or six-word phrase two dozen times without realising it — “plays an important role in the”, “as can be seen from the”. The Unusual Phrase Repetition panel surfaces those crutches so your writing reads varied and deliberate instead of formulaic. This is the kind of thing a supervisor circles in red, and it is trivial to fix once you can see it laid out.
Verifying an AI-assisted draft still reads human
Using an AI tool to get past a blank page is fine at most schools — handing in raw, unedited AI output is not. Run your draft through the AI Content Analysis to see which sentences read as machine-generated: uniform lengths, a pile-up of transition phrases, low burstiness. Wherever the score is high, rewrite in your own voice until the signals drop. It is a mirror for your editing, not a verdict.
Comparing two of your own drafts
If you rewrote an assignment but are not sure how much genuinely changed, paste both versions in together. Any sentences that survived word-for-word from the first draft show up as duplicates, giving you a quick, honest read on whether you actually revised or just shuffled things around. Students resubmitting improved coursework use this to confirm the new version is meaningfully different.
Frequently Asked Questions
❓ Is this plagiarism checker really free?
Yes, 100% free. No signup, no credit card, no usage limits.
❓ Can I upload Word documents?
Yes, .docx and .txt are supported. For .doc files, save as .docx first.
❓ Is there a character limit?
No. You can paste entire theses or research papers — no limit.
❓ Is my document private?
Completely. Everything runs in your browser. Your text never leaves your device.
❓ Can it check against websites?
No — that requires a server. Use the "Verify Online" buttons to manually search on Google and Google Scholar.
❓ Is this a free AI content detector?
Yes. It works as a free AI content detector using 7 statistical signals: sentence uniformity, burstiness, transition-phrase density, vocabulary richness, word length, passive-voice ratio, and hedging language.
❓ What score should I aim for?
Originality above 80% is generally safe. AI likelihood below 30% is low-risk. Always verify with your institution's policy.
❓ Will Turnitin flag what this tool flags?
Not exactly. Turnitin compares your text against a huge database of web pages, journals, and past student papers — this tool cannot do that. But the repeated sentences and reused paragraphs this tool finds inside your own document are the same things Turnitin counts as self-plagiarism, so cleaning them up here removes a real source of matches before you submit.
❓ How do I check plagiarism against the web for free?
No free browser-only tool can truly scan the whole web, because that requires a paid search index. The honest workaround is manual: use the "Verify Online" buttons above to search your most distinctive sentences on Google and Google Scholar. If a sentence returns an exact match in quotes, that source is where it came from.
❓ Is AI-content detection accurate?
It is a signal, not a verdict. This tool measures statistical patterns — sentence uniformity, transition-phrase density, burstiness — that AI writing tends to show. Human writing can occasionally trip these signals and edited AI can pass them, so treat a high score as a prompt to review specific sentences, never as proof. No AI detector, paid or free, is reliable enough to accuse someone on its own.
Want to understand how this tool works in depth?
Read the full story — how two university students used this tool to check their SRS project report before submission, what signals the AI detection uses, and exactly what this tool can and cannot do.
100% Private. Your documents are never uploaded to any server. All analysis runs in your browser. No data collection. Works offline after page load.