Download Bazel – Fast and Scalable Multi-Language Build System

Bazel is a free, open-source build and test tool developed by Google that supports projects of any size, from small libraries to massive monorepos spanning multiple programming languages. It is designed for speed, reproducibility, and scalability — the same build system used internally at Google for projects like Android, TensorFlow, and Google Search.

Bazel uses a declarative BUILD file syntax (similar to Python) to define build targets and their dependencies. Its incremental build engine only rebuilds files that have actually changed, and its distributed caching and remote execution support allow teams to share build artifacts across machines — dramatically reducing build times in large codebases.

It supports Java, C++, Python, Go, JavaScript, TypeScript, Kotlin, Scala, Swift, and many other languages through a rich ecosystem of official and community rules. Bazel integrates with popular IDEs, CI/CD systems, and containerized build environments, making it a versatile choice for organizations adopting monorepo strategies or polyglot development workflows.

Key Features

• Incremental builds – Only rebuilds what has changed; tracks all inputs and outputs precisely for fast, correct builds.
• Remote caching and execution – Share build artifacts via a remote cache and distribute build tasks across multiple machines.
• Hermetic builds – Sandboxed build environment ensures reproducible, deterministic outputs regardless of the host machine.
• Multi-language support – Build Java, C++, Python, Go, JavaScript, Kotlin, Swift, and more in a unified build graph.
• Scalable to monorepos – Designed to handle massive codebases with thousands of targets and millions of files efficiently.
• Integrated testing – Built-in test runner with caching of passing tests and parallel test execution.
• Extensible rule system – Add support for new languages or tools using Starlark (a Python-like language) custom rules.

How to Install

1. Download the Bazelisk launcher (recommended) or the Bazel binary from the link below — Bazelisk automatically downloads the correct Bazel version for your project.
2. On Linux/macOS, make the binary executable: chmod +x bazelisk-linux-amd64 && sudo mv it to /usr/local/bin/bazel.
3. On Windows, download the .exe and add it to your system PATH.
4. In your project root, create a WORKSPACE file (or MODULE.bazel for Bzlmod) to declare your project and external dependencies.
5. Write BUILD files defining your build targets and run bazel build //path/to:target to build or bazel test //... to run all tests.