Regular expression for removing blank lines

A concise regex example for removing repeated blank lines from text files, form input or copied content.

Consecutive blank lines are common in user input: copy-paste, form submissions, or differing line endings between operating systems all produce them. This regular expression removes them.

It targets the run of whitespace before a line break and replaces it with a single line break. The whitespace class covers tabs and carriage returns as well as plain spaces, so it works with both Windows and Unix line endings.

Use the global flag to clean the whole text; otherwise only the first match is replaced.

\s+\n

To review examples of how to use this expression, you can click here.

Short guide

When to use it

This expression can clean repeated blank lines from form fields, description text and imported content. It is practical in blogs, admin panels and CMS screens where editor output should stay tidy.

What to watch

Run the regex globally; otherwise only the first match changes.
If one blank line should remain between paragraphs, soften the rule accordingly.
A preview before saving helps users understand what was changed.

Common mistake

Regex should not be treated as the answer to every formatting issue. Sometimes an HTML sanitizer, parser or editor setting is the better tool.

Before using this in a project

Regex examples are useful shortcuts, but real projects should also consider the data source, line endings, browser/server differences and user input mistakes. In web forms, admin panels and custom software, validation should not live only on the frontend; the server side should check it too.