Similarity refers to how closely text matches existing sources, measured as a percentage by plagiarism detection tools. Plagiarism is an ethical and academic judgment—it occurs when someone presents another person's work as their own without attribution, regardless of the similarity percentage.
A high similarity score does not automatically mean plagiarism. A paper with 25% similarity made up entirely of correctly cited quotations is not plagiaristic. Conversely, a paper with a 3% similarity score could still contain plagiarism if a key idea was taken from a source without citation. Always read the full report, not just the number. Our guide on what is a plagiarism test explains how to interpret your results correctly. Run your document through Quetext's Plagiarism Checker for a full breakdown.