Text Similarity Checker
Enter text in both fields to compare them.
What is Text Similarity Checker
The Text Similarity Checker compares two blocks of text and scores how closely they match using cosine similarity over word-frequency vectors. It tokenizes both texts, strips common stop words, then measures the overlap between what's left, returning a percentage plus the exact words the two texts share and the words unique to each one. Everything runs locally in your browser, so neither text ever leaves your device.
How to use
- Paste or type the first text into the left field.
- Paste or type the second text into the right field.
- Read the similarity percentage and the shared and unique word lists below.
- Edit either text and watch the score update instantly.
When to use it
Comparing two drafts of the same paragraph to see how much you actually changed? Paste the before and after versions and you might see 62% similarity, with words like 'revenue' and 'quarter' shared but 'growth' only in the new draft. It also works well for spotting near-duplicate product descriptions, checking how close a paraphrase stays to its source, or seeing whether two survey answers are really saying the same thing in different words.
Frequently asked questions
How is the similarity score calculated?
The tool tokenizes both texts into words, removes common stop words like 'the' and 'and', then builds a word-frequency vector for each text and measures the cosine similarity between them. The result is a percentage from 0% (no shared vocabulary) to 100% (identical word usage).
Does word order matter?
No. Cosine similarity on word-frequency vectors ignores order and grammar, so 'the cat chased the dog' and 'the dog chased the cat' score as fully similar. It measures vocabulary overlap, not sentence structure or meaning.
Why do two similar-sounding texts sometimes score lower than expected?
The score only counts words that survive stop-word filtering, so two paraphrases that use different vocabulary for the same idea, like 'car' versus 'vehicle', share fewer terms even though they mean the same thing. Treat the percentage as a vocabulary-overlap measure, not a meaning-detection score.
Is this the same as a plagiarism checker?
Not quite. This tool measures vocabulary overlap between two texts you provide, which is useful for comparing drafts, paraphrases, or duplicate content. A plagiarism checker also searches the web or a document database for matches, which this tool does not do.
Can I share this tool with my inputs pre-filled?
Yes. The URL updates automatically as you type. Copy it from the address bar or use the Share button, and anyone who opens the link will see both texts ready to go.
Related tools
Atbash Cipher Encoder and Decoder
Encode and decode the Atbash cipher online. Atbash mirrors the alphabet and is its own inverse, so one click scrambles and unscrambles. Free and private.
Convert Binary to Text
Decode binary code back to readable text instantly. Tolerant of missing zeros and unspaced bit streams. Free online binary to text converter.
Caesar Cipher Decoder
Decode Caesar cipher text online. Set the shift or try all 25 at once to crack an unknown key. Free, instant, and private in your browser.