Is my text sent to any server?

No. All processing happens entirely in your browser using JavaScript. Your text is never uploaded or stored anywhere.

What does the similarity percentage mean?

The score is the Jaccard similarity of unique words in both texts: the number of shared unique words divided by the total unique words across both texts, expressed as a percentage. A score above 30% suggests significant overlap.

What counts as a matched phrase?

The tool finds bigrams (2-word sequences) and trigrams (3-word sequences) that appear in both texts. These are shown highlighted in each panel and listed below the results.

Does punctuation affect the results?

Punctuation is stripped before comparison, and all text is lowercased. This ensures "Hello," and "hello" are treated as the same word.

Can I use this to guarantee academic honesty?

This tool is a quick client-side indicator, not a comprehensive plagiarism database. For institutional use, always combine it with a professional plagiarism detection service.

What is a good similarity score?

Scores under 10% typically indicate unique texts. 10–30% may reflect shared terminology. Above 30% often signals substantial overlap worth reviewing.

Text Similarity Checker

Name: Text Similarity Checker
Availability: InStock
Author: Nham Vu

Paste two texts and instantly see their similarity score with matched phrases highlighted — all processed locally in your browser.

Text A (Original / Reference)

0 words

Text B (Submitted / Comparison)

0 words

Summary

Paste two texts and instantly see their similarity score with matched phrases highlighted — all processed locally in your browser.

How it works

Paste or type the first text in the left panel.
Paste or type the second text in the right panel.
Click "Compare Texts" to start the analysis.
The tool tokenizes both texts into words and n-grams (bigrams and trigrams).
Jaccard similarity is calculated: |intersection| / |union| of word sets.
Matching phrases are highlighted in both panels and listed below the results.

Use cases

Check whether a student submission overlaps with a reference text.
Detect paraphrased or duplicated content across two documents.
Compare two versions of an article to find reused passages.
Verify originality before submitting an essay or research paper.
Identify copied sections when reviewing peer assignments.
Compare a draft against a published source for accidental similarity.
Audit AI-generated text against source material.
Measure how much two documents share in common vocabulary.

Frequently Asked Questions

Last updated: 2026-06-10 · Reviewed by Nham Vu