Plagiarism Checker — Repetition & Text Similarity
Detect repeated phrases and duplicate sentences in your writing, or compare two documents for text similarity. All analysis runs in your browser — your text is never sent to any server.
Enter at least 10 words to analyse.
This tool checks for repetition and similarity within the text provided. It does not search the internet or external databases.
How the Plagiarism Checker Works
- 1Choose Repetition Check (single text) or Text Similarity (two texts).
- 2Paste your text into the input area(s).
- 3The tool scans for repeated 4-word phrases and duplicate sentences and displays a repetition score.
- 4Review the flagged phrases and rewrite overused sections to improve originality.
Repetition vs. Internet Plagiarism
This tool checks your writing for internal repetition and similarity to another document you provide. It does not crawl the web. For submitting academic work, also run your paper through your institution's recommended plagiarism service (Turnitin, iThenticate, or similar) which compares against web pages, published papers, and student submission databases.
Tips for Original Writing
Check your own draft first
Run your draft through Repetition Check before submission. Flagged phrases are often signs of copy-paste habits, unintentional self-plagiarism, or simply weak vocabulary variety.
Compare paraphrases
Paste your paraphrase and the original source into Text Similarity mode. A similarity score under 25% suggests the paraphrase is sufficiently original. Above 50% means you should rewrite more substantially.
Paraphrase, then cite
Putting source material into your own words is not enough on its own — you must still cite the original. Plagiarism is about attribution, not just word-for-word copying.
Use synonyms strategically
If the checker flags a recurring phrase, look for a technical synonym or restructure the sentence. Variety in phrasing is also a sign of a richer vocabulary to an instructor.
Frequently Asked Questions
Does this check against the internet?
No. This tool checks for repetition within your own text and similarity between two texts you provide. It does not search the web or any external database. For full web-based plagiarism detection, use a service like Copyscape or Turnitin.
What does the Repetition Score mean?
The repetition score estimates the percentage of your text that consists of repeated 4+ word phrases. A score below 15% is normal. Above 35% suggests significant repetition that may weaken your writing or indicate over-reliance on a source.
What is the Text Similarity mode?
Text Similarity compares two texts you paste and computes a cosine similarity score based on shared 3-word phrases (trigrams). 0% means no shared phrasing; 100% means identical texts.
Is my text stored or sent to any server?
No. All analysis runs client-side in JavaScript. Your text never leaves your device. This tool is completely private.
What counts as a "duplicate sentence"?
Any sentence of 4 or more words that appears more than once in your text is flagged as a duplicate. Intentional repetition for rhetorical effect (anaphora) may be flagged — use your judgment when reviewing results.
How can I reduce my repetition score?
Identify the flagged phrases in the results panel. Replace repeated terms with synonyms, restructure sentences to use different phrasing, or remove redundant sections entirely.