Cómo Compare Two Files Using Notepad++ and Other Tools

Comparing two files to find differences is a common task when troubleshooting configuration changes, reviewing code modifications, or verifying file integrity. This guide covers multiple methods for comparing files on Windows, from lightweight text editors to dedicated comparison tools and command-line utilities.

Method 1: Notepad++ Compare Plugin

Notepad++ is a popular free text editor that supports file comparison through its Compare plugin. This is one of the easiest ways to visually compare two text files side by side.

Installing the Compare Plugin

1. Open Notepad++.
2. Go to Plugins > Plugins Admin (or Plugin Manager > Show Plugin Manager in older versions).
3. In the Available tab, search for Compare.
4. Check the box next to Compare and click Install.
5. Restart Notepad++ when prompted.

Comparing Two Files

1. Open both files in Notepad++ (each in its own tab).
2. Go to Plugins > Compare > Compare (or press Alt + D).
3. Notepad++ will split the view into two side-by-side panels showing both files with differences highlighted.

Understanding the Comparison Results

The Compare plugin uses color coding to indicate changes:

Color	Meaning
Green	Lines added (present in one file but not the other)
Red/Pink	Lines removed
Yellow/Orange	Lines that are changed (present in both but modified)
Highlighted characters	Specific characters within a changed line that differ

A navigation panel on the right side shows an overview of the entire file with colored markers indicating where differences occur.

Additional Compare Plugin Options

• Plugins > Compare > Settings: Configure colors, navigation bar position, and comparison behavior.
• Plugins > Compare > Clear Results: Remove the comparison highlighting and return to normal view.
• Navigation: Use the Next and Previous buttons (or keyboard shortcuts) to jump between differences.

Method 2: WinMerge

WinMerge is a free, open-source dedicated comparison and merge tool for Windows that handles both files and folders.

Key Features

• Side-by-side file comparison with syntax highlighting
• Folder comparison showing which files differ between directories
• Three-way merge support
• Regular expression-based line filters
• Integration with version control systems

Uso

1. Download and install WinMerge from winmerge.org.
2. Open WinMerge and click File > Open (or press Ctrl + O).
3. Select the two files (or folders) to compare.
4. Click OK to start the comparison.
5. Differences are highlighted with color coding similar to Notepad++.
6. Use the merge buttons to copy changes from one side to the other.

WinMerge is particularly strong for folder comparisons, where you need to see which files differ across entire directory structures.

Method 3: Visual Studio Code Built-In Diff

VS Code includes a built-in file diff viewer that works without any extensions.

Comparing Two Open Files

1. Open both files in VS Code.
2. Right-click one of the file tabs and select Select for Compare.
3. Right-click the other file tab and select Compare with Selected.
4. VS Code opens a side-by-side diff view with changes highlighted.

Comparing from the Command Line

code --diff file1.txt file2.txt

Comparing from the Command Palette

1. Press Ctrl + Shift + P to open the Command Palette.
2. Type Compare and select File: Compare Active File With….
3. Select the file to compare against.

VS Code’s diff view supports inline and side-by-side modes, toggled with the button in the editor toolbar.

Method 4: Windows fc Command

The fc (File Compare) command is built into every version of Windows and works from the command prompt without any installation.

Basic Uso

fc file1.txt file2.txt

Common Options

Flag	Description
/B	Binary comparison
/C	Case-insensitive comparison
/L	Compare files as ASCII text (default)
/N	Display line numbers (ASCII comparison only)
/W	Compress white space during comparison
/T	Do not expand tabs to spaces

Ejemplos

:: Compare two text files with line numbers
fc /N config_old.xml config_new.xml

:: Case-insensitive comparison
fc /C file1.txt file2.txt

:: Binary comparison
fc /B program_v1.exe program_v2.exe

:: Redirect output to a file
fc /N file1.txt file2.txt > differences.txt

The fc command outputs the lines that differ between the two files, along with surrounding context lines to help locate the changes.

Method 5: PowerShell Compare-Object

PowerShell’s Compare-Object cmdlet provides a more flexible approach to file comparison.

Basic Line-by-Line Comparison

# Compare two files line by line
Compare-Object (Get-Content file1.txt) (Get-Content file2.txt)

Output shows:

Symbol	Meaning
<=	Line exists only in the first file (left side)
=>	Line exists only in the second file (right side)

Detailed Comparison with Line Numbers

# Compare with line numbers
$file1 = Get-Content "C:\path\file1.txt"
$file2 = Get-Content "C:\path\file2.txt"

$comparison = Compare-Object $file1 $file2 -IncludeEqual

$comparison | ForEach-Object {
    $indicator = switch ($_.SideIndicator) {
        "==" { "SAME" }
        "<=" { "ONLY IN FILE1" }
        "=>" { "ONLY IN FILE2" }
    }
    [PSCustomObject]@{
        Line    = $_.InputObject
        Status  = $indicator
    }
}

Comparing File Hashes

To check if two files are identical without examining content:

# Compare file hashes
$hash1 = Get-FileHash "file1.txt" -Algorithm SHA256
$hash2 = Get-FileHash "file2.txt" -Algorithm SHA256

if ($hash1.Hash -eq $hash2.Hash) {
    Write-Host "Files are identical"
} else {
    Write-Host "Files differ"
}

Method 6: Git Diff

If you have Git installed, you can use its diff command even for files not in a repository:

git diff --no-index file1.txt file2.txt

This provides a unified diff output with additions shown in green and deletions in red (when color output is enabled).

Choosing the Right Tool

Tool	Best For	Pros	Cons
Notepad++ Compare	Quick text comparisons	Lightweight, good for config files	Plugin required, text files only
WinMerge	File and folder comparisons	Free, merge support, folder diffs	Separate installation needed
VS Code	Developer workflows	Built-in, no extensions needed	Heavier than Notepad++
fc command	Command-line scripting	No installation, available everywhere	Basic output, no merge
PowerShell	Automated comparisons	Scriptable, flexible output	More complex syntax
Git diff	Developer environments	Rich diff output, widely available	Requires Git installation

Resumen

For quick visual file comparisons, the Notepad++ Compare plugin provides an easy-to-use side-by-side view with color-coded differences. WinMerge offers more advanced features including folder comparison and merge capabilities. VS Code includes a built-in diff viewer ideal for developers. For command-line needs, the Windows fc command works without any installation, while PowerShell’s Compare-Object enables scriptable comparisons. Choose the tool that fits your workflow, whether that is a lightweight editor plugin for occasional comparisons or a dedicated tool for regular code review and configuration management tasks.