How to use the similarity checker
- Paste the first text, such as your draft, into the left box.
- Paste the second text, such as a source or another answer, into the right box.
- Select Compare texts to see how much of each text appears in the other, with shared passages highlighted.
About this tool
The checker looks for runs of identical words that appear in both texts. On the normal setting, any five words in a row that match are highlighted, which catches copied sentences even when a few words around them were changed.
It compares only the two texts you paste. It doesn't search the internet or other people's work, so it's best for checking a draft against a specific source, comparing two answers, or seeing how closely a paraphrase still follows the original.
Questions
Is this a plagiarism checker?
It compares two texts that you provide. A full plagiarism check compares your work against the whole internet and published papers, which needs a paid database.
What does the match length setting do?
It's how many words in a row must match. Strict (8 words) finds only longer copied passages; Loose (3 words) also flags common short phrases.
Why are the two percentages different?
Each shows how much of that text is shared. A paragraph copied into a long essay is a large share of the paragraph but a small share of the essay.