ToolSpotAI

Text Similarity & Readability Analyzer

Local analysis: readability, vocabulary diversity, internal repetition. Compare two pasted texts for similarity—does not search the web.

Writing

Runs entirely in your browser

Analyze one text for readability and repetition, or compare two pasted texts for similarity. This does not search the web or academic databases—use your school or a paid service for that.

0 words

Local analysis only: readability metrics and patterns inside the text(s) you paste. To check against published sources on the internet, use a dedicated plagiarism database or your institution’s tool.
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What is Text Similarity & Readability Analyzer?

This tool helps writers and editors improve drafts and compare two versions locally. It measures readability (Flesch Reading Ease, Flesch-Kincaid Grade Level), vocabulary diversity, internal repetition, and—when you paste two texts—structural similarity with n-grams. It is not a substitute for Turnitin-style database checks against published work. Use it to tune clarity and to see how similar two passages are when both are already on your clipboard.

How It Works

In Analyze mode: paste your text and get instant metrics — uniqueness score, word/character/sentence counts, vocabulary diversity, Flesch readability scores, and any repeated phrases. In Compare mode: paste two texts and see the similarity percentage, number of overlapping phrases, and any matching sentences highlighted.

Formula

Flesch Reading Ease = 206.835 − (1.015 × ASL) − (84.6 × ASW)
Flesch-Kincaid Grade = 0.39 × ASL + 11.8 × ASW − 15.59
Vocabulary Diversity = Unique Words / Total Words × 100
Similarity = Overlapping n-grams / Total n-grams × 100

Formula Explained

ASL = Average Sentence Length (words per sentence). ASW = Average Syllables per Word. The Flesch formula rewards shorter sentences and simpler words. The Kincaid grade level approximates US school grade needed to understand the text. Vocabulary diversity measures how varied your word choices are.

Example

Text: 500 words, 25 sentences Flesch Reading Ease: 65.2 (Standard) Flesch-Kincaid Grade: 8.3 (8th grade) Vocabulary Diversity: 62% Uniqueness Score: 88% (Mostly Unique) Repeated phrases found: 1 Avg sentence length: 20 words Avg word length: 4.8 characters

Tips & Best Practices

  • ✓Aim for a Flesch Reading Ease of 60+ for web content and blog posts.
  • ✓Vary your vocabulary to improve diversity — use a thesaurus for repeated words.
  • ✓Keep sentences under 20 words on average for readability.
  • ✓Use Compare mode to check paraphrased content against the original.
  • ✓For professional plagiarism detection, combine this tool with Turnitin or Copyscape.

Common Use Cases

  • •Editors comparing two drafts for overlap
  • •Content writers analyzing readability for target audiences
  • •Bloggers scanning a post for repeated phrasing
  • •Students reviewing essays locally before submitting elsewhere
  • •Teachers comparing two short submissions side by side

Frequently Asked Questions

No. Everything runs in your browser. It scores readability and internal repetition in one text, and compares two pasted texts with n-gram overlap. It does not search the web or proprietary paper databases. For database-backed plagiarism review, use your institution’s tool or a paid service.

The Flesch Reading Ease score ranges from 0-100. Higher = easier to read. 60-70 is standard (8th-9th grade). 80+ is very easy. Below 30 is very difficult (college graduate level). It is based on average sentence length and syllables per word. Aim for 60+ for general audiences.

Vocabulary diversity (also called lexical diversity) is the ratio of unique words to total words. Higher diversity = richer vocabulary = generally better writing. Below 40% may indicate repetitive content. Academic writing typically shows 55-70% diversity.

The comparison mode uses 4-gram analysis (overlapping sequences of 4 words) to measure structural similarity between texts. It reliably detects copied or closely paraphrased passages but may not catch heavily reworded content. For professional plagiarism detection, use dedicated services.

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