content_copy Duplicate Content Checker
Find repeated passages, clichés and filler in your writing - or compare two documents for overlap. Runs entirely in your browser.
No check yet
Add at least 10 words, then run a check to see repeated passages, clichés, filler words and full writing statistics.
This tool finds passages you have repeated within a document, measures how much two documents overlap, and flags clichés and filler words that weaken your writing - with colour-coded highlighting, full writing statistics, and a report you can download as PDF, DOCX or TXT. Everything runs in your browser, so your text is never uploaded.
Frequently asked questions
No, and this is the most important thing to understand about it. Checking whether text was copied from the web requires a search index of billions of pages, which only paid commercial services have. This tool compares your text against ITSELF (and optionally against a second document you provide). A clean result here does NOT mean your text is free of material copied from the internet.
Three things it does exactly, not approximately: finding passages you have accidentally repeated in a long document; measuring how much two of your own documents overlap (useful for self-plagiarism, reused boilerplate, or checking a rewrite is genuinely different); and flagging clichés and filler that make writing weaker. Because it is real string matching rather than a guess, what it reports is precise.
Click "Compare with another text" above the editor, paste your second document into the box that appears, then run the check. You will get an overlap percentage showing how much of the first text also appears in the second.
Any run of six or more consecutive words that appears more than once. Shorter matches are ignored because ordinary English repeats short word sequences constantly, which would produce noise rather than useful findings.
Red marks a passage repeated elsewhere in the document, orange marks a cliché or overused phrase, and yellow marks a filler word. Unhighlighted text was not flagged. Clicking any highlight selects the matching entry in the findings list.
No. The entire analysis runs on your own device in JavaScript - your text never leaves the browser, is never sent to this site, and is not stored anywhere. That also means it keeps working offline once the page has loaded.
Not necessarily - they are suggestions, not errors. Phrases like "in order to" or "at the end of the day" are usually worth cutting, but context matters and sometimes the familiar phrasing is the right choice. Treat the list as a prompt to look again, not a rule.
This tool accepts plain .txt files directly. For a PDF, run it through the PDF to Text tool first and paste the result here. Keeping the analysis text-only is what allows it to run instantly in your browser without downloading a document parser.