Remove Blank Lines

Removes blank lines from a block of text. A line is treated as blank if it contains nothing or only whitespace (spaces, tabs). All non-empty lines stay in their original order.

Useful for cleaning up text pasted from PDFs, fixing double-spaced paragraphs, or normalising multi-line output before further processing.

When you reach for this

Cleaning text from PDFs

Copy-pasting from a PDF often inserts empty lines between paragraphs. Strip them in one pass before formatting.

Fixing double-spaced output

Some apps insert an empty line after every paragraph. Removing the blanks gives you tightly-packed prose.

Pre-processing for code

If you're feeding text to a parser line-by-line, removing blanks reduces edge cases.

Cleaning chat transcripts

Slack and Discord exports include empty lines between messages — strip them to get a compact transcript.

Tightening lists

Lists with empty separator lines look loose. Strip the blanks for tighter visual rhythm.

What gets processed (and how)

The tool reads the input text and splits it into an array of lines using the newline character (\n) as delimiter. For each line, it tests whether the trimmed string matches the regular expression /^\s*$/ — a line that contains zero or more whitespace characters (spaces, tabs, carriage returns) is considered blank. Lines that do not match are collected into a new array preserving their original order. The tool handles both Unix (LF) and Windows (CRLF) line endings by normalizing line breaks before processing. After filtering, the non-blank lines are joined back with the original line-ending style (LF or CRLF) to maintain consistency with the input. The algorithm runs in O(n) time relative to the number of lines, making it efficient even for large texts.

How to use it

1. Paste or type your text into the input area.
2. Click the 'Remove Blank Lines' button.
3. Verify the cleaned output appears in the result box.
4. Copy the result or download it as a text file.

Behavior on tricky inputs

Trailing newlines

A single trailing newline is preserved as it follows the last non-blank line; multiple trailing newlines are treated as blank lines and removed.

CRLF vs LF line endings

The tool normalizes line endings to LF internally, so mixed line endings are handled consistently, and the output uses the original style.

Whitespace-only lines

Lines containing only spaces, tabs, or carriage returns are considered blank and removed, leaving visibly empty lines intact.

Workflow tips

• Use after pasting text from a PDF to remove spurious line breaks while preserving paragraph structure.
• Combine with a trim tool to remove leading/trailing whitespace from each line before blank-line removal.
• Run on code to eliminate empty lines that break syntax highlighting or linting in some editors.
• Process multiple files by concatenating them with a separator, removing blank lines, then splitting again.

vs other ways to do this

Compare with common alternative methods for removing blank lines.

Where this came from

The practice of removing blank lines originates from early Unix text processing utilities. The grep command, introduced in 1974 by Ken Thompson, could filter lines matching a pattern; grep -v '^$' became a standard idiom to delete empty lines. Later, sed offered in-place editing with sed '/^$/d'. These tools, designed for stream editing and pipeline use, established the paradigm of efficient, pattern-based line removal that modern web tools like this one emulate.