Plagiarism Checker Online

Is this Text Similarity Checker free?

Yes. The tool is completely free to use with no subscriptions, registrations, or hidden charges.

Is my text uploaded to a server?

No. All comparisons are performed locally in your browser using JavaScript. Your text is never uploaded, stored, or shared.

How does the similarity checker work?

The tool compares both texts using Jaccard similarity on word n-grams. It measures how many word sequences are shared between the two texts relative to the total number of unique word sequences, producing a similarity score that reflects their level of overlap.

What is Jaccard similarity?

Jaccard similarity is a mathematical measure used to compare two sets. In this tool, each text is broken into word n-grams, and the similarity score is calculated by dividing the number of shared n-grams by the total number of unique n-grams across both texts.

What is a word n-gram?

A word n-gram is a sequence of consecutive words. For example, with an n-gram size of 2, the sentence "The quick brown fox" becomes: "The quick", "quick brown", "brown fox". Comparing n-grams helps identify matching phrases rather than just individual words.

Does the tool highlight matching text?

Yes. Matching words and phrases shared between both texts are highlighted, making it easy to see exactly where content overlaps.

Is this a plagiarism checker?

No. This tool is not a full plagiarism detection service. It only compares the two texts you provide and does not search websites, books, journals, or academic databases for matching content.

What does the similarity percentage mean?

The similarity score indicates how much content the two texts have in common based on shared word n-grams. Higher percentages generally indicate more overlapping phrases, while lower percentages suggest the texts are more distinct.

Does formatting affect the results?

The comparison focuses on textual content rather than formatting. Differences in fonts, colors, or styling do not influence the similarity calculation.

Can I compare large documents?

Yes. There is no fixed document size limit imposed by the tool. Processing speed depends mainly on your browser and device when analyzing very large texts.

Can I compare source code?

The tool is designed primarily for natural language text such as articles, essays, documentation, and reports. While it can compare code as plain text, the similarity score may not accurately reflect structural differences in programming languages.

Can I use this tool on mobile devices?

Yes. The Text Similarity Checker works in all modern desktop and mobile browsers without requiring installation.

Who can use this tool?

This tool is useful for students, teachers, writers, editors, researchers, SEO professionals, content marketers, developers, technical writers, and businesses reviewing duplicate content.

Why should I use a Text Similarity Checker?

A Text Similarity Checker helps you quickly identify overlapping content between two documents without manually reviewing every line. It is useful for checking revisions, validating rewritten content, comparing reports, reviewing AI-generated text, auditing website content, and ensuring originality before publication.