Sublime Text Quick Tip: Removing Empty Lines in Sublime Text: Regex, Selections, and a One-Key Plugin

By Manny Fernandez

September 29, 2026

Sublime Text Quick Tip: Removing Empty Lines in Sublime Text: Regex, Selections, and a One-Key Plugin

Objective: Strip blank and whitespace-only lines out of config dumps, log exports, and pasted CLI output in Sublime Text, either across the whole file or only inside a selection, and bind the whole thing to a single key.

Target audience: Network and security engineers who live in Sublime Text and are tired of cleaning up show full-configuration output by hand.

Prerequisites and Architecture

Everything here uses built-in Sublime Text features. The plugin section uses the Python API that ships with Sublime Text 4, so there is nothing to install.

Component	Requirement
Editor	Sublime Text 4 (Build 4xxx). Sublime Text 3 works for the regex steps.
Assumed knowledge	Basic regex: `^` is start of line, `\n` is a newline.
Line endings	Any. Sublime normalizes CRLF to `\n` in the buffer, so the same patterns work on Windows files.
Sample file	Any text file with blank lines. A FortiGate config backup or a pasted debug capture is ideal.

Keyboard reference

Action	Windows / Linux	macOS
Open Find and Replace	Ctrl + H	Option + Command + F
Toggle regular expressions	Alt + R	Option + Command + R
Toggle In Selection	Alt + S	Option + Command + S
Find All (select every match)	Alt + Enter	Option + Enter
Replace All	Ctrl + Alt + Enter	Click Replace All

Step-by-Step Implementation

Step 1: Open Find and Replace in regex mode

Goal: Get the replace panel open with regular expressions turned on.

Action: Press Ctrl + H (Option + Command + F on macOS), then press Alt + R (Option + Command + R) or click the .* button on the left of the panel.

GUI verification: The .* button is highlighted. If it is not, every pattern below is treated as literal text and will match nothing.

Step 2: Remove truly empty lines

Goal: Delete lines that contain nothing at all.

Action: Put this in the Find field, leave Replace empty, and hit Replace All.

^\n

This matches a newline that sits at the very start of a line, which only happens on an empty line. Deleting it pulls the next line up.

Step 3: Remove whitespace-only lines (the one you actually want)

Goal: Also catch lines that look empty but hold spaces or tabs, which is common in pasted terminal output and indented config blocks.

Action: Use this pattern with an empty Replace field.

^\h*\n

\h is horizontal whitespace: spaces, tabs, and non-breaking spaces that sneak in when you copy from a browser or a Word doc. If you prefer something more explicit, ^[ \t]*\n does the same job for plain spaces and tabs.

Why not ^\s*\n? Because \s includes the newline itself, so it can swallow a run of blank lines plus the leading indentation of the next real line. On an indented FortiOS config that silently breaks your nesting.

Step 4: Collapse runs of blank lines to a single blank line

Goal: Keep paragraph or block separation but kill the five-line gaps.

Action: Find the pattern below and replace with \n\n. In regex mode Sublime turns \n in the Replace field into a real newline.

\n(\h*\n){2,}

Read it as: a line ending, followed by two or more blank (or whitespace-only) lines. That whole block becomes one line ending plus exactly one blank line.

Step 5: Limit the cleanup to a selection

Goal: Clean one section, like a single config firewall policy block, and leave the rest of the file alone.

Action: Highlight the lines first, open Find and Replace, then press Alt + S (Option + Command + S) to turn on In Selection before running Replace All with any pattern above.

GUI verification: The In Selection button (the icon with lines inside a box) is highlighted, and only the highlighted region changes.

Step 6: Turn it into a one-key command with a plugin

Goal: Stop retyping regex. One keystroke cleans the selection, or the whole file if nothing is selected.

Action: Go to Tools, Developer, New Plugin. Replace the template with the code below and save it as remove_empty_lines.py in the default location (your Packages/User folder).

import sublime
import sublime_plugin


class RemoveEmptyLinesCommand(sublime_plugin.TextCommand):
    """Delete empty and whitespace-only lines in the selection or file."""

    def run(self, edit):
        view = self.view
        scopes = [s for s in view.sel() if not s.empty()]
        if not scopes:
            scopes = [sublime.Region(0, view.size())]

        targets = [
            r for r in view.find_all(r"^\h*\n")
            if any(scope.contains(r) for scope in scopes)
        ]

        # Erase bottom-up so earlier offsets stay valid
        for region in reversed(targets):
            view.erase(edit, region)

        sublime.status_message(
            "Removed {} empty line(s)".format(len(targets))
        )

Sublime reloads plugins on save, so the command remove_empty_lines exists immediately. Now bind it. Open Preferences, Key Bindings, and add this to the right-hand (User) pane. Pick any chord that is free on your setup.

[
    { "keys": ["ctrl+alt+e"], "command": "remove_empty_lines" }
]

Optional: add it to the Command Palette. Create Packages/User/RemoveEmptyLines.sublime-commands with:

[
    { "caption": "Text: Remove Empty Lines", "command": "remove_empty_lines" }
]

GUI verification: Press your chord. The status bar at the bottom reports how many lines were removed, and a single Ctrl + Z (Command + Z) puts them all back.

Verification and Validation

Before and after any cleanup, count the blank lines so you know exactly what changed. Open Find (Ctrl + F or Command + F) with regex on and search for:

^\h*$

Press Find All (Alt + Enter or Option + Enter). The status bar shows the match count as a number of selection regions. Expected success output after Step 3: Find All reports no matches, apart from a possible single empty line at the very end of the file (see the gotchas below).

For configs, also sanity-check that structure survived: search for ^\h*end$ before and after. The count should be identical.

Troubleshooting and Gotchas

Replace All says 0 matches

Nine times out of ten the regex toggle is off, or In Selection is still on from a previous search and nothing is selected. Check both buttons on the left side of the panel. Also confirm Whole Word is off, since it wraps your pattern in word boundaries and breaks it.

Blank lines at the end of the file will not go away

The patterns above need a trailing newline to match, and the last line of a file may not have one. To trim everything after the last real line down to a single newline, find the pattern below and replace with \n.

\s+\z

To make this automatic, add these to Preferences, Settings (User pane). They also stop whitespace-only lines from being created in the first place.

{
    "trim_trailing_white_space_on_save": "all",
    "ensure_newline_at_eof_on_save": true
}

Lines still look blank after the cleanup

Something invisible is on them, usually a zero-width space or a stray carriage return from a mixed-ending paste. Add "draw_white_space": ["all"] to your settings to reveal them, then widen the character class:

^[\h\r\x{200B}\x{FEFF}]*\n

If the file came from Windows tooling, also run View, Line Endings, Unix and save, so every line ends consistently before you clean it.

Quick reference: empty lines ^\n, whitespace-only lines ^\h*\n, collapse gaps \n(\h*\n){2,} to \n\n, trailing blanks \s+\z to \n. Regex toggle on, every time.

Sublime Text Quick Tip: Removing Empty Lines in Sublime Text: Regex, Selections, and a One-Key Plugin

Prerequisites and Architecture

Keyboard reference

Step-by-Step Implementation

Step 1: Open Find and Replace in regex mode

Step 2: Remove truly empty lines

Step 3: Remove whitespace-only lines (the one you actually want)

Step 4: Collapse runs of blank lines to a single blank line

Step 5: Limit the cleanup to a selection

Step 6: Turn it into a one-key command with a plugin

Verification and Validation

Troubleshooting and Gotchas

Replace All says 0 matches

Blank lines at the end of the file will not go away

Lines still look blank after the cleanup

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