How to Use .gitignore in Git: A Complete Guide

In any software project, not all files should be tracked by Git. From compiled binaries and environment configurations to IDE settings and logs, keeping unnecessary files out of your Git repository is critical for maintaining a clean and efficient codebase. That’s where .gitignore comes in.

In this article, we’ll cover everything you need to know about how to use .gitignore effectively, including syntax, common use cases, and best practices.

Table of Contents

What Is `.gitignore`?

.gitignore is a simple text file that tells Git which files or directories to ignore in a project. Git will skip tracking or staging any files that match the patterns defined in this file.

This is especially useful for:

Build artifacts (e.g., dist/, *.class)
Environment files (e.g., .env)
System files (e.g., .DS_Store, Thumbs.db)
Dependencies (e.g., node_modules/, vendor/)

Creating a `.gitignore` File

To create a .gitignore file:

Navigate to your project root.
Create the file:

touch .gitignore

Open the file in a text editor and list patterns for files you want Git to ignore.

Basic Syntax

Each line in a .gitignore file specifies a pattern. Here are the basic rules:

Syntax	Meaning
`#`	Comment line
`*.log`	Ignores all `.log` files
`temp/`	Ignores the entire `temp` directory
`/config.php`	Ignores only the file in the root directory
`!important.txt`	Exception: do not ignore this file

Examples:

# Logs
*.log

# Node dependencies
node_modules/

# Build outputs
dist/
build/

# Environment variables
.env

# macOS system files
.DS_Store

Ignoring Files Already Tracked

If a file is already being tracked by Git and you add it to .gitignore, it will still be tracked until you explicitly remove it:

git rm --cached filename

Then commit the change:

git commit -m "Remove filename from tracking"

Using Global `.gitignore`

You can define a global .gitignore for files you want Git to ignore across all projects, such as IDE settings or OS-specific files.

Create a global ignore file (e.g., ~/.gitignore_global)
Configure Git to use it:

git config --global core.excludesfile ~/.gitignore_global

Common `.gitignore` Templates

Instead of writing a .gitignore from scratch, use community-maintained templates:

Visit https://github.com/github/gitignore
Choose one for your language/framework (e.g., Python, Node.js, Java)

You can also use the gitignore.io generator to create a custom one based on technologies you use.

Best Practices

Add a .gitignore file at the beginning of your project.
Do not ignore files that are critical to building or understanding the project.
Use comments to explain non-obvious ignores.
Share .gitignore with your team—commit it to the repo.

Conclusion

Using .gitignore effectively is an essential skill for any developer working with Git. It helps keep repositories clean, reduces noise in commits, and protects sensitive or environment-specific data from being inadvertently shared.

Whether you’re starting a new project or cleaning up an existing one, setting up a solid .gitignore file will pay dividends in the long run.

What Is .gitignore?

Creating a .gitignore File