LibreOffice 6.2 (February 2019) and later support regular expressions based on the International Components for Unicode (ICU). RegexBuddy knows exactly which version of ICU that each version of LibreOffice from 6.2 to 25.8 (August 2025) is built with. So you only need to select your version of LibreOffice in RegexBuddy to make sure the regular expressions you create and test with RegexBuddy will work exactly the same in LibreOffice.
In LibreOffice Writer, you can select Edit|Find & Replace in the menu or press Ctrl+H to search your document using a regular expression, and optionally make replacements as well. You can copy and paste your regular expressions and replacement strings directly between this dialog box and RegexBuddy.
LibreOffice Calc has a single REGEX() function that you can use in your formulas to extract a regex match, replace a regex match, or replace all regex matches. RegexBuddy can generate a formula that uses your regex for any of these 3 purposes that you can then paste into LibreOffice Calc. You can also copy and paste just the regular expression by selecting RegexMagic Formula under the Copy or Paste button in RegexBuddy.
First, use RegexBuddy to define a regex or retrieve a regex saved in a RegexBuddy library. Rely on RegexBuddy’s clear regex analysis, which is constantly updated as you build the pattern, rather than dealing with the cryptic regex syntax on your own. Detailed help on that syntax is always only a click away.
If you created a new regular expression, test and debug it in RegexBuddy before using it in your actual application. Test each regex in RegexBuddy’s safe sandbox without risking precious data. Quickly apply the regex to a wide variety of input and sample data, without having to produce that input through your application.