Whether you’re developing Java applications or running Java-based software, you’ll need to install OpenJDK. This comprehensive guide will walk you through downloading and installing OpenJDK on every major operating system, with step-by-step instructions that anyone can follow.
1. What is OpenJDK?
OpenJDK (Open Java Development Kit) is the open-source implementation of Java SE (Java Platform, Standard Edition). This project began in 2006 and is now developed collaboratively by Oracle and the community, available for free under the GPL v2 license.
Since Java 7, OpenJDK has been the official reference implementation of Java SE, and it’s now the standard choice for most development environments worldwide.
2. OpenJDK Download and Installation
2.1 Installing OpenJDK on Windows
Windows users have several excellent options for installing OpenJDK.
Method 1: Microsoft Build of OpenJDK (Recommended)
- Visit the Microsoft OpenJDK download page
- Download the .msi file for your desired version (e.g., Java 17, Java 21)
- Run the downloaded .msi file and follow the installation wizard
- Environment variables will be configured automatically upon completion
Method 2: Eclipse Temurin (AdoptOpenJDK) Installation
- Go to the Eclipse Adoptium download page
- Select your desired OpenJDK version
- Choose Windows as your operating system and download the .msi installer
- Run the downloaded .msi file and follow the installation wizard
Method 3: Manual Installation with ZIP Files
- Download the Windows ZIP file from the official OpenJDK website
- Extract the ZIP file to your preferred location (e.g., C:\Program Files\Java)
- Set up environment variables manually:
- Navigate to Control Panel > System > Advanced System Settings > Environment Variables
- Create a new system variable called ‘JAVA_HOME’ and set it to your JDK installation path (e.g., C:\Program Files\Java\jdk-21)
- Edit the Path variable and add ‘%JAVA_HOME%\bin’
Verifying Installation on Windows
Open Command Prompt and run:
java -version
If you see Java version information displayed, your installation was successful.
2.2 Installing OpenJDK on macOS
macOS users can choose from several installation methods.
Method 1: Homebrew Installation (Recommended)
- Open Terminal
- Verify Homebrew is installed by running:
brew --version - If Homebrew isn’t installed, install it with:
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)" - Install OpenJDK:
brew install --cask temurin # Latest LTS version - For specific versions, use:
brew install --cask temurin8 # Java 8brew install --cask temurin11 # Java 11brew install --cask temurin17 # Java 17brew install --cask temurin21 # Java 21 - For Microsoft’s build:
brew install --cask microsoft-openjdk
Method 2: Manual Binary Package Installation
- Download the macOS .tar.gz file from the official OpenJDK website
- Double-click the downloaded file to extract it
- Open Terminal and move the extracted JDK folder to the appropriate location:
sudo mv ~/Downloads/jdk-21.jdk /Library/Java/JavaVirtualMachines/ - Enter your password when prompted for administrator privileges
Verifying Installation on macOS
Open Terminal and run:
java -version
If you see Java version information displayed, your installation was successful.
2.3 Installing OpenJDK on Linux
Linux installation methods vary depending on your distribution.
Ubuntu/Debian-based Distributions
- Update your package list:
sudo apt update - Install OpenJDK:
sudo apt install openjdk-17-jdk # JDK 17 installation - For other versions, simply change the version number:
sudo apt install openjdk-8-jdk # JDK 8sudo apt install openjdk-11-jdk # JDK 11sudo apt install openjdk-21-jdk # JDK 21
CentOS/RHEL/Fedora-based Distributions
- Install OpenJDK:
sudo dnf install java-17-openjdk-devel # JDK 17 installation - For other versions, change the version number:
sudo dnf install java-1.8.0-openjdk-devel # JDK 8sudo dnf install java-11-openjdk-devel # JDK 11sudo dnf install java-21-openjdk-devel # JDK 21
Arch Linux Distribution
- Install OpenJDK:
sudo pacman -S jdk-openjdk # Latest JDK installation - For specific versions:
sudo pacman -S jdk8-openjdksudo pacman -S jdk11-openjdksudo pacman -S jdk17-openjdk
Manual Binary Package Installation (All Linux Distributions)
- Download the Linux .tar.gz file from the official OpenJDK website
- Extract the downloaded file:
tar -xzf openjdk-21_linux-x64_bin.tar.gz - Move the extracted folder to your preferred location:
sudo mv jdk-21 /opt/ - Set up environment variables by opening ~/.bashrc and adding these lines:
export JAVA_HOME=/opt/jdk-21export PATH=$JAVA_HOME/bin:$PATH - Apply the changes:
source ~/.bashrc
Verifying Installation on Linux
Run this command in Terminal:
java -version
If you see Java version information displayed, your installation was successful.
3. Java Version Management and Verification
3.1 Checking Your Installed Java Version
You can verify your Java installation by running this command in Terminal or Command Prompt:
java -version
If your JDK is properly installed, you’ll see output similar to:
openjdk version "21.0.2" 2023-01-17
OpenJDK Runtime Environment (build 21.0.2+13-LTS)
OpenJDK 64-Bit Server VM (build 21.0.2+13-LTS, mixed mode, sharing)
3.2 Managing Multiple Java Versions
Here’s how to install and switch between multiple Java versions as needed.
Managing Multiple Versions on Windows
- Install each version in separate directories
- Change the JAVA_HOME system environment variable to point to your desired version
- Update the Path variable accordingly
Using SDKMAN! on macOS and Linux
SDKMAN! is a powerful tool for managing multiple SDK versions:
- Install SDKMAN!:
curl -s "https://get.sdkman.io" | bash - Restart your terminal or run:
source "$HOME/.sdkman/bin/sdkman-init.sh" - List available Java versions:
sdk list java - Install your desired version:
sdk install java 21.0.2-tem - Set the default version:
sdk default java 21.0.2-tem - Switch versions temporarily:
sdk use java 17.0.5-tem
4. Major OpenJDK Distributions Overview
Various companies and organizations provide OpenJDK-based builds. You can choose the distribution that best fits your needs.
4.1 Eclipse Temurin (formerly AdoptOpenJDK)
- Provider: Eclipse Foundation
- Features: Vendor-neutral, TCK tested, high quality
- Recommended for: Both development and production environments
- Download: Eclipse Adoptium
4.2 Microsoft Build of OpenJDK
- Provider: Microsoft
- Features: Optimized for Windows and Azure environments
- Recommended for: Microsoft ecosystem and Azure cloud
- Download: Microsoft OpenJDK
4.3 Amazon Corretto
- Provider: Amazon
- Features: AWS-optimized, long-term support
- Recommended for: AWS cloud environments
- Download: Amazon Corretto
4.4 Azul Zulu
- Provider: Azul Systems
- Features: Stable builds, commercial support available
- Recommended for: Enterprise environments, production systems
- Download: Azul Zulu
4.5 Red Hat OpenJDK
- Provider: Red Hat
- Features: RHEL-optimized
- Recommended for: Red Hat Enterprise Linux environments
- Download: Red Hat OpenJDK
5. OpenJDK Version Selection Guide
5.1 LTS (Long-Term Support) Versions
LTS versions receive security updates and bug fixes for extended periods. We recommend LTS versions for production environments.
Current OpenJDK LTS versions:
- Java 8: Released March 2014, still widely used in legacy systems
- Java 11: Released September 2018
- Java 17: Released September 2021
- Java 21: Released September 2023, the latest LTS version
5.2 Non-LTS Versions
Non-LTS versions are released every six months and include the latest features, but have shorter support periods. They’re ideal for testing new features or development environments.
Current latest non-LTS version:
- Java 24: Released March 2024
6. Essential OpenJDK Usage Tips
6.1 Environment Variable Configuration
Most Java-based tools use the JAVA_HOME environment variable to locate your JDK installation. Make sure it’s properly configured.
6.2 Security Updates
Regular security updates are crucial for OpenJDK, especially in production environments. Keep your installation current with the latest patches.
6.3 Memory Configuration
You can optimize Java application performance by adjusting JVM memory settings:
java -Xms512m -Xmx1024m -jar myapp.jar
- Xms: Initial heap size
- Xmx: Maximum heap size
6.4 Garbage Collection Tuning
For large-scale applications, you can select and tune garbage collection algorithms:
java -XX:+UseG1GC -jar myapp.jar # Use G1 garbage collector
7. Frequently Asked Questions
Q: What are the main differences between OpenJDK and Oracle JDK?
A: OpenJDK is open-source and free to use, while Oracle JDK may require licensing fees for commercial use. Functionally, recent versions are nearly identical.
Q: Which OpenJDK distribution should I choose?
A: It depends on your development or deployment environment. For general use, Eclipse Temurin is recommended. For specific cloud environments, use the respective provider’s distribution (e.g., Corretto for AWS).
Q: How do I update OpenJDK?
A: Update methods vary by distribution and installation method. If installed via package manager, use that manager to update. For manual installations, download and replace with the new version.
Q: What’s the difference between JDK and JRE?
A: JDK (Java Development Kit) includes tools needed for Java application development, while JRE (Java Runtime Environment) only provides the environment needed to run Java applications.
Q: Which Java version should I choose?
A: For production environments, we recommend the latest LTS version (currently Java 21) for stability. If you have legacy code compatibility concerns, consider Java 17 or Java 11.
This guide has covered OpenJDK download and installation methods, various distributions, and version selection guidelines. OpenJDK allows you to build a high-quality Java development environment at no cost, and choosing the right distribution for your environment and purpose is key to success. Stay current with the latest Java development trends while maintaining a stable production environment by using LTS versions and applying regular security updates.