Text Similarity Checker
Quickly compare two blocks of text and see how similar they are. Choose between word‑level comparison (great for paraphrasing checks) or character‑level comparison (perfect for spotting minor edits). Get a percentage score, word overlap stats, and a visual progress bar. No signup, no data uploads — everything happens right in your browser.
Why use this similarity checker?
Whether you're comparing two versions of a document, checking for accidental duplication, or just curious how alike two blocks of text are, this tool gives you an instant, objective score. It's perfect for writers, editors, developers, and students who need a quick, private similarity check without uploading files to a cloud service.
- Two comparison modes – Word‑level uses the Jaccard index (intersection over union of unique words), which is great for understanding content overlap. Character‑level uses normalized Levenshtein distance, which catches small edits and typos.
- Case‑sensitivity toggle – decide whether "Hello" and "hello" should count as different words.
- Detailed stats – see the number of common words and unique words per text, or the edit distance and maximum length.
- Instant results – the comparison updates as you type (with a short delay) or when you click Compare.
- 100% private – all processing happens locally; your texts never leave your device.
How to compare texts (step‑by‑step)
1. Enter two texts
Paste or type the two pieces of text you want to compare into the left and right boxes.
2. Choose a method
Select word‑level for content similarity, or character‑level for precise edit distance. Toggle case sensitivity if needed.
3. Get the score
The similarity percentage appears instantly along with a progress bar. Scroll down to see detailed word or character stats.
4. Copy or clear
Click "Copy Score" to grab the percentage for your records, or "Clear" to start a new comparison.
Example comparisons
| Text 1 | Text 2 | Word‑level similarity | Character‑level similarity |
|---|---|---|---|
| The quick brown fox jumps over the lazy dog | The quick brown fox jumps over the lazy dog | 100% | 100% |
| The quick brown fox jumps over the lazy dog | A slow red cat sleeps under the active dog | ~7% | ~22% |
| I love programming in JavaScript | I enjoy coding in JavaScript | ~20% | ~40% |
Common use cases
- Plagiarism checking: Quickly compare a student's paper against a source text to see lexical overlap.
- Document versioning: Measure how much an article has changed between drafts.
- Paraphrase detection: Check if two sentences convey similar content using different wording.
- Code similarity: Use character‑level comparison to find duplicate code snippets (whitespace‑sensitive).
- SEO content audit: Ensure multiple blog posts on a similar topic aren't too close in wording.
Pro tips
- Word‑level comparison strips punctuation and treats "cat" and "Cat" as the same word (unless you enable case‑sensitive). It's ideal for detecting similar topics and phrases.
- Character‑level comparison is more precise but can be slower on very large texts. Use it when you need to spot minor edits or typos.
- For large documents, word‑level is lightning fast. You can paste entire articles and get a score instantly.
- The similarity percentage is rounded to one decimal place. A score above 60% often indicates substantial overlap; below 20% usually means very different content.