Plagiarism-style Duplicate Content Checker (harder to build well, skip if resources limited). Free duplicate content checker. Compare two texts for matching phrases or find repeated sentences in one text. Instant results, private and no signup.
Want to know how much of your text matches another piece of writing? Our free Duplicate Content Checker compares two texts, highlights every matching phrase and gives you a clear similarity percentage. You can also paste a single text to find repeated sentences and phrases, which is handy for cleaning up website copy, essays and articles. Adjust the minimum match length to be as strict or relaxed as you like. Everything runs in your browser, so your text is never uploaded or stored. Note that the tool compares the texts you paste and does not search the internet.
How to use (shown below the tool)
- Choose Compare two texts or Find repeated content in one text.
- Pick a minimum match length. Five words is a good starting point, and a lower number is stricter.
- Paste your text into the first box. In compare mode, paste the source text into the second box.
- Click Check Content.
- Review the percentages and the highlighted passages, then rewrite anything that matches too closely.
- Use Swap to reverse the two texts, Sample to try an example, or Clear to start over.
FAQs
Does this tool check the whole internet for plagiarism?
No. It compares the texts you paste, or looks for repetition inside a single text. It does not search websites or databases.
How is the similarity percentage calculated?
The tool looks for runs of matching words, based on the minimum match length you choose. The percentage is the share of your text covered by those matches.
What match length should I choose?
Five words works well for most content. Choose 3 to catch short matches, or 8 to 12 to ignore common phrases and see only longer copied passages.
Can I use it to find duplicate content on my own website?
Yes. Paste two pages’ text to compare them, or paste one page to find sentences and phrases that repeat inside it.
Is my text saved or uploaded?
No. All checking happens in your browser and nothing is sent to a server.
Is the Duplicate Content Checker free?
Yes. It is free, needs no registration and has no usage limits.
