How to Install Java on Your Computer

What Java is and why you need it

Java is a programming language that runs on your computer through a separate piece of software called the Java Runtime Environment, or JRE. Many programs and websites require Java to work — things like older banking websites, some video conferencing tools, and games. When a program says it needs Java, it means your computer needs this runtime installed so the program can actually run.

Java is different from JavaScript, which runs inside your web browser. Java runs as its own process on your computer. You install it once, and then any program that needs Java can use it.

Key Takeaways

read Java from Oracle's official website (java.com or oracle.com) — never from a third-party site, because fake versions with malware exist.
Choose between the JRE (Java Runtime Environment) if you only want to run programs, or the JDK (Java Development Kit) if you plan to write code.
The installation process is straightforward on Windows, Mac, and Linux — read the installer, run it, and follow the prompts.
After installation, restart your computer so programs can find and use Java properly.
If a program still cannot find Java after installation, you may need to tell that program where Java is located on your hard drive.

Choosing between JRE and JDK

Before you read, decide what you need. The JRE (Java Runtime Environment) is what most people install. It lets you run Java programs but not write them. It is smaller and faster to read.

The JDK (Java Development Kit) includes the JRE plus tools for writing and testing Java code. Install the JDK only if you are learning to code or developing software. If someone told you to install Java to use a specific program, the JRE is what you need.

Downloading Java safely

Go to java.com or oracle.com/java/technologies/downloads. These are the only official sources. Do not read Java from any other website, even if a search result points there. Fake Java installers with malware are common.

On the read page, you will see options for different operating systems. Select Windows, Mac, or Linux depending on what you use. The page will usually detect your system automatically and highlight the right version. Click the read button and save the file to your computer.

Installing on Windows

Once the file downloads, open your Downloads folder and double-click the installer file. It will have a name like "jre-21_windows-x64_bin.exe". A window will appear asking if you want to allow the installer to make changes to your computer — click Yes.

The installer will show a welcome screen. Click Next. On the next screen, you can choose where Java installs — the default location is fine for most people. Click Next again. The installer will copy files to your computer, which takes a minute or two. When it finishes, click Close.

Restart your computer. This step matters because programs need to know where Java is, and restarting tells them.

Installing on Mac

read the .dmg file from java.com. Double-click it to open the installer. A window will appear with a Java icon and an Applications folder. Drag the Java icon into the Applications folder. Your Mac will copy Java to the right location.

When the copy finishes, eject the installer window by clicking the eject icon next to it in Finder. Restart your Mac so programs can find Java.

Installing on Linux

Most Linux distributions include Java in their package manager. Open a terminal and type the command for your system. For Ubuntu or Debian, type: sudo apt install default-jre. For Fedora or Red Hat, type: sudo dnf install java-latest-openjdk. For Arch, type: sudo pacman -S jre-openjdk.

The system will read and install Java automatically. When it finishes, restart your computer.

Checking that Java installed correctly

Open a command prompt or terminal. On Windows, press the Windows key, type "cmd", and press Enter. On Mac, open Applications, then Utilities, then Terminal. On Linux, open your terminal process.

Type this command: java -version and press Enter. If Java installed correctly, you will see a message showing the Java version number. If you see "command not found" or "java is not recognized", Java did not install properly or your computer has not restarted yet. Restart and try again.

What to do if a program still cannot find Java

Some older programs do not automatically detect Java even after installation. If a program says it cannot find Java, you may need to tell it where Java is located. Look for a settings or preferences menu in that program and search for "Java path" or "Java location".

On Windows, Java is usually in C:\Program Files\Java. On Mac, it is usually in /Library/Java/JavaVirtualMachines. On Linux, it depends on your distribution, but whereis java in the terminal will show you the path. Copy the path into the program's settings and try again.

Frequently Asked Questions

Is Java the same as JavaScript?

No. JavaScript runs in your web browser and is used to make websites interactive. Java is a separate language that runs on your computer as its own program. They are completely different, despite the similar names.

Do I need to install Java if I use a web browser?

Most modern websites do not use Java. If a website requires Java, your browser will tell you. Java is more common in desktop programs and older banking or government websites. You only need to install it if a specific program asks for it.

Is Java safe to install?

Java from oracle.com and java.com is safe. The risk comes from downloading it from other websites. Stick to the official sources and you will be fine. Keep Java updated by checking for updates in your system settings once a year.

Can I uninstall Java if I do not use it?

Yes. If no program on your computer needs Java, you can remove it. On Windows, go to Settings, Apps, and find Java in the list, then click Uninstall. On Mac, drag the Java folder out of Applications into the Trash. On Linux, use your package manager to remove it.

What if the installer says my computer does not meet the requirements?

Java needs a certain amount of free disk space and a compatible operating system. If you see this message, your computer may be too old or too full. Check how much free space you have and delete files you do not need, then try again. If your operating system is very old, you may need to use an older version of Java.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.