Windows supports text files natively and also incorporates a search function, but it doesn't go out of its way to put the two together. MuseTips Text Filter is a compact, portable, and free tool that can quickly and thoroughly search text files. It searches as you type and displays matching terms in contrasting colors. It also offers autosuggestions, full support for regular expressions, multiple query modes, and extensive filtering.
At less than 500KB unzipped, Text Filter is certainly lightweight, and since it's fully portable, it runs from any location, including from a USB drive or other portable device. Its interface is spartan, with a blank main view; File, Search, View, and Help menus; and New, Open, and Save icons. We browsed to a text file, opened it, and entered some terms in the program's search field. Text Filter uses incremental searching, or "search as you type," a useful enhancement that displays progressively more selective results as you enter more letters or words. The chief advantage of this type of searching lies in its ability to find similar spellings, misspellings, closely related words, and other near misses that very often lead to useful hits. Text Filter highlighted our search hits in yellow inside the text, displaying whole sentences and phrases and altering its results in real time as we typed. While it doesn't offer many settings, we could hide or display the Tool Bar and Status Bar, select Word Wrap, and hide matched or unmatched lines from the View menu; select Naive, Smart, and Regex queries as well as the Match Case and Auto-Suggest options from the Search menu; and access recently viewed files from the File menu.
MuseTips Text Filter is a great tool for searching through text files. Coders will like its specificity and its options, but anyone can benefit from its ability to search text files much more quickly, thoroughly, and accurately than the Windows search tool can manage.