See exactly what two texts share
Paste two texts (two drafts, a source and a summary, an original and a paraphrase) and the checker highlights every passage they share, in both texts. It works with word sequences: two passages count as shared when at least n consecutive words (four by default) are identical, after ignoring case and punctuation.
The scores
- Coverage: the share of each text that sits inside shared passages. If a summary has 60% coverage, more than half of it is copied word for word.
- Jaccard similarity: overlap between the two sets of n-word phrases, from 0% (nothing shared) to 100% (identical phrasing).
- Cosine similarity: how similar the vocabulary is, regardless of word order. Two texts about the same topic score high on cosine even when written independently.
Shorter phrase lengths (3 words) catch more, including common expressions; longer ones (7 words) find only clear copying.
What this is not
This compares only the two texts you paste. It doesn’t search the web or a database of papers, so it can’t tell you whether text was copied from somewhere else. For checking your own paraphrasing against a source, though, it’s precise and completely private.
Worked example
Here is what the Text Similarity Checker returns for its built-in example. Settings used: Match phrases of: 4+ words; Ignore common words: off. Click Try an example in the tool above to load it, then change it as you like.
Readability formulas estimate how difficult a text is to read. They rely on sentence length and word length, and they were designed for general audiences rather than specialists.
(compared with)
Most readability formulas estimate how difficult a text is to read by looking at sentence length and word length. They were designed for students, not specialists.| Result | Value |
|---|---|
| First text covered | 68% |
| Second text covered | 73% |
| Jaccard (phrases) | 26% |
| Cosine (vocabulary) | 78% |
| Shared passages | 3 |
Questions
Is this a plagiarism checker?
It compares two texts you provide and shows their overlap. It does not search the internet or academic databases.
What similarity percentage means copying?
There is no universal threshold. Long shared passages (7+ words) in the highlights are the clearest sign of copied wording.
Last reviewed · How Textkiln tools work