Duplicate Text Comparison
Paste two versions of a text: the tool computes their similarity, lists the shared sentences and highlights what was added or removed.
Privacy and cost
This tool runs in your browser. What you type or paste is not sent to our servers and it costs nothing to use.
How it works
- Paste the original text into box A and the text to compare into box B.
- Run the comparison: the tool aligns the words of both texts and computes the similarity.
- Read the highlights (removals in red, additions in green) and the list of identical sentences.
Example
Two descriptions of 17 and 18 words that differ only by "meta" added and "in your browser" replaced with "on our servers": 80% similarity, 34.8% shared 3-word phrases and 1 identical sentence ("Results appear in seconds.").
What the result means
Similarity compares words in order: 100% means identical texts (case and edge punctuation ignored). The 3-word phrase overlap is stricter and reveals copied passages. This is an estimate, not a plagiarism verdict, and Google has not published a "duplicate content" threshold.
Common problems this tool helps with
- Product pages or city pages that differ by only a few words.
- Text taken from another site with light rewording.
- A new version of an article where you want to see exactly what changed.
- Category descriptions that are too close from one page to the next.
Frequently asked questions
What similarity level risks duplicate content?
There is no official threshold. Above roughly 80%, two pages read as duplicates: differentiate them, merge them or use a canonical tag.
What is the maximum text size?
About 200,000 characters per box, and 3,000 words per text are aligned to stay fast. A warning appears when input is truncated.
Does the comparison care about letter case?
No. Capitals and punctuation at word edges are ignored: "Hello," and "hello" are the same.
Are my texts sent anywhere?
No. The comparison runs in your browser.
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