Searches in text files for Samurai Search are line based. Samurai Search no longer has a built in limit on line length.

Searches in PDF files are page based. Searches may match across lines in a page, in which case the results will show the matching lines. Note that searching in PDF is inherently difficult because of the complex ways in which characters can be rendered on the page.

Samurai Search regular expression search conforms to the ICU specification for regular expressions. See also a one page quick reference and a website devoted to regular expressions.