If the lines in a text document appear several times, then the manual examination of the document might prove to be difficult. The use of an online tool may come in handy in this situation. All you have to do is paste the text in an online tool that willremove duplicate lines online from the text and keep only the unique ones. This process will prove to be useful in the case of a list, copied information, keywords, links, or notes. It is important to check the text before the processing.