Google Closure Compiler

Overview

Google Closure Compiler is ranked #7 of 27 in JavaScript build tools on Specifiction. It runs on Linux, macOS, Self-hosted, Windows. There is a free plan.

Compared on JavaScript build tools

Free plan

Yesdevelopers.google.com

TypeScript support

Nodevelopers.google.com

Code splitting

Yesdevelopers.google.com

Tree shaking

Yesdevelopers.google.com

Source maps

Yesdevelopers.google.com

Plugin API

Yesdevelopers.google.com

Facts

Purpose

Closure Compiler optimizes JavaScript by analyzing it, removing dead code, rewriting and minimizing what remains, and checking syntax, references, and types.developers.google.com · 4 Oct 2026

File efficiency

Google says the compiler reduces JavaScript file size and can help applications load faster while reducing bandwidth needs.developers.google.com · 4 Oct 2026

Code checking

The compiler warns about illegal JavaScript, potentially dangerous operations, and common JavaScript pitfalls.developers.google.com · 4 Oct 2026

Compilation modes

Available compilation levels include WHITESPACE_ONLY, SIMPLE, and ADVANCED; the repository README also lists BUNDLE.github.com · 4 Oct 2026

Advanced optimization

ADVANCED_OPTIMIZATIONS can improve compression through aggressive transformations and symbol renaming, and requires care to preserve program behavior.developers.google.com · 4 Oct 2026

Ways to use

The project page describes an open source command-line Java application, a library used via Bazel, and an NPM package.developers.google.com · 4 Oct 2026

Distribution

The project page directs users to download a released JAR from Maven, and the repository README also documents Maven distribution.developers.google.com · 4 Oct 2026

NPM package

The repository README states that NPM packages are built and distributed by an open source contributor, not by Google.github.com · 4 Oct 2026

Build requirements

The repository README lists Java 21 or later, NodeJS, Git, and Bazelisk as requirements to build the compiler.github.com · 4 Oct 2026

JavaScript restrictions

The repository says Closure Compiler places restrictions on input, including use of goog.module() and goog.require(), and that ES6 import/export support is not actively maintained.github.com · 4 Oct 2026

Security and compliance

The project page links to the Apache 2.0 license for code samples; it does not state a security certification or compliance standard.developers.google.com · 4 Oct 2026

Help

Google’s FAQ directs users to the Closure Compiler Discuss Group, Stack Overflow, and the FAQ itself for help.developers.google.com · 4 Oct 2026

Integrations

The repository documents a NodeJS API and use through Maven, NPM, Bazel, and command-line Java.github.com · 4 Oct 2026

Intended use

The repository says Google projects use Closure Compiler to reduce JavaScript size, check code, support localization, transpile newer JavaScript features, and split output into loadable chunks.github.com · 4 Oct 2026

Where it ranks on Specifiction

• Best JavaScript Build Tools in 2026#7 of 27

Sources

• developers.google.com/closure/compiler· checked 4 Oct 2026
• github.com/google/closure-compiler· checked 4 Oct 2026
• developers.google.com/closure/compiler/docs/api-tutorial3· checked 4 Oct 2026
• developers.google.com/closure/compiler/faq· checked 4 Oct 2026