Step-by-Step Guide: How to Install and Set Up JDK in 2026

This guide walks you through installing the JDK (Java Development Kit) on your computer: downloading, installing, and configuring environment variables. The steps are shown on Windows; brief sections for macOS and Linux are below.

You can also choose between Oracle JDK and OpenJDK. OpenJDK (for example, Eclipse Temurin builds) is free for any use and functionally identical. Oracle JDK is also free for development but has licensing nuances for some commercial scenarios. Either works for learning; the steps below use Oracle JDK.

The installation has five steps:

1. Downloading the JDK Package

Start by downloading the JDK package. You can download it from the Oracle website. Oracle is the company that owns Java's rights. You can download any version on this page. At the time of writing this guide, the current version is Java 26, but LTS is Java 25. So it is recommended to install Java 25 (on the screens it is older version, but all steps are the same).

Choose your operating system—Linux, macOS, or Windows—and then select the file type for download:

2. Installing JDK

After downloading the file, simply click on the downloaded .exe file and the following window will appear:

From here, just click "Next" on almost all steps.

In the next step, you can choose a different directory for installation. By default, it’s set to C:\Program Files\Java:

I’ll leave it as it is, click "Next," and the installation process will begin. You’ll see a status window showing the copying of new files, and finally, it’s almost done:

Click "Close" to finish the installation. But there’s still more to do.

3. Adding the JAVA_HOME Variable

Next, we need to set up the JAVA_HOME system variable. One way to do this is to search for "Edit the system environment variables":

Go to the Environment Variables section:

In the system variables section, click "New" to create a new variable:

Enter the variable name JAVA_HOME in uppercase with underscores, and in the value field, specify the path to your Java directory, e.g., C:\Program Files\Java\jdk-25:

Click "OK."

4. Updating the Path Variable

Another necessary step is to update the Path variable. In the list of environment variables, find Path and click "Edit":

Carefully, without removing anything, click "New":

Add the line %JAVA_HOME%\bin and click "OK". It’s recommended to move the newly added line to the top:

5. Verifying the Correctness of the Java Installation

Finally, let’s check if Java is installed correctly. Open the Command Prompt by typing cmd in the search bar.

In the Command Prompt, type the following command:

java -version

If everything is fine, you will see the installed version of Java displayed:

Now, the Java installation is complete, and you can start writing Java programs.

6. Installing on macOS and Linux

macOS

The easiest way is the Homebrew package manager. In the terminal, run:

brew install openjdk@25

After installing, Homebrew tells you how to add the JDK to your PATH. Alternatively, download a .dmg installer from Oracle or Adoptium and install it like any app. The check is the same:

java -version

Linux (Ubuntu/Debian)

Install OpenJDK from the repository:

sudo apt update
sudo apt install openjdk-25-jdk

Verify with

java -version

If you have several Java versions, switch between them with

sudo update-alternatives --config java

7. Common installation problems

'java' is not recognized as an internal or external command. The most common error. It means the path to the JDK isn't in your Path variable (step 4), or the command prompt wasn't restarted. Close and reopen the command prompt, and check that Path contains %JAVA_HOME%\bin.

java -version shows an old version. If Java was installed before, an old path may remain in Path. Make sure %JAVA_HOME%\bin is listed above other Java paths, and that JAVA_HOME points to the right folder.

JAVA_HOME isn't recognized. Check that the variable is set under System variables (not User), the name is uppercase — JAVA_HOME — and the path points to the JDK root (e.g. C:\Program Files\Java\jdk-25), without \bin at the end.

Frequently asked questions