kb/data/developer.mozilla.org/en-US/docs/Glossary/Tree_shaking-0.md

title	chunk	source	category	tags	date_saved	instance
Tree shaking - Glossary | MDN	1/3	https://developer.mozilla.org/en-US/docs/Glossary/Tree_shaking	reference	web, html, css, javascript, documentation	2026-05-05T05:47:27.237642+00:00	kb-cron

• Skip to main content
• Skip to search

MDN HTML HTML: Markup language

HTML reference

• Elements
• Global attributes
• Attributes
• See all…

HTML guides

• Responsive images
• HTML cheatsheet
• Date & time formats
• See all…

Markup languages

• SVG
• MathML
• XML

CSS CSS: Styling language

CSS reference

• Properties
• Selectors
• At-rules
• Values
• See all…

CSS guides

• Box model
• Animations
• Flexbox
• Colors
• See all…

Layout cookbook

• Column layouts
• Centering an element
• Card component
• See all…

JavaScriptJS JavaScript: Scripting language

JS reference

• Standard built-in objects
• Expressions & operators
• Statements & declarations
• Functions
• See all…

JS guides

• Control flow & error handing
• Loops and iteration
• Working with objects
• Using classes
• See all…

Web APIs Web APIs: Programming interfaces

Web API reference

• File system API
• Fetch API
• Geolocation API
• HTML DOM API
• Push API
• Service worker API
• See all…

Web API guides

• Using the Web animation API
• Using the Fetch API
• Working with the History API
• Using the Web speech API
• Using web workers

All All web technology

Technologies

• Accessibility
• HTTP
• URI
• Web extensions
• WebAssembly
• WebDriver
• See all…

Topics

• Media
• Performance
• Privacy
• Security
• Progressive web apps

Learn Learn web development

Frontend developer course

• Getting started modules
• Core modules
• MDN Curriculum
• Check out the video course from Scrimba, our partner

Learn HTML

• Structuring content with HTML module

Learn CSS

• CSS styling basics module
• CSS layout module

Learn JavaScript

• Dynamic scripting with JavaScript module

Tools Discover our tools

• Playground

• HTTP Observatory

• Border-image generator

• Border-radius generator

• Box-shadow generator

• Color format converter

• Color mixer

• Shape generator

About Get to know MDN better

• About MDN

• Advertise with us

• Community

• MDN on GitHub

Blog

1. Glossary
2. Tree shaking

Tree shaking

Tree shaking is a term commonly used within a JavaScript context to describe the removal of dead code. It relies on the import and export statements to detect if code modules are exported and imported for use between JavaScript files. In modern JavaScript applications, we use module bundlers (e.g., webpack or Rollup) to automatically remove dead code when bundling multiple JavaScript files into single files. This is important for preparing code that is production ready, for example with clean structures and minimal file size.

In this article

• See also

See also

• "Benefits of dead code elimination during bundling" in Axel Rauschmayer's book: "Exploring JS: Modules"
• Tree shaking implementation with webpack