Java Swing – Difference Between java.exe and javaw.exe

See Java tools documentation for:

• java command¹/javaw command²

1. The java tool launches a Java application. It does this by starting a Java runtime environment, loading a specified class, and invoking that class's main method.
2. The javaw command is identical to java, except that with javaw there is no associated console window. Use javaw when you don't want a command prompt window to appear.

• javaws command, the "Java Web Start command"

The javaws command launches Java Web Start, which is the reference implementation of the Java Network Launching Protocol (JNLP). Java Web Start launches Java applications/applets hosted on a network.

If a JNLP file is specified, javaws will launch the Java application/applet specified in the JNLP file.

The javaws launcher has a set of options that are supported in the current release. However, the options may be removed in a future release.

See also JDK 9 Release Notes Deprecated APIs, Features, and Options:

Java Deployment Technologies are deprecated and will be removed in a future release
Java Applet and WebStart functionality, including the Applet API, the Java plug-in, the Java Applet Viewer, JNLP and Java Web Start, including the javaws tool, are all deprecated in JDK 9 and will be removed in a future release.

• jvm.dll is the actual Windows implementation of the JVM (or better, the main entry point). C or C++ applications can use this DLL to run an embedded Java runtime, and that would allow the application to interface directly with the JVM, e.g. if they want to use Java for its GUI.

• java.exe is a wrapper around the DLL so that people can actually run Java classes without the need for a custom launcher application. It is a Win32 Console application, so Windows will open a fresh Command Prompt window if the exe is not run from a batch file.

• javaw.exe is a wrapper like java.exe, but it is a Win32 GUI application. Windows doesn't have to open a Command Prompt window, which is exactly what you want to run a GUI application which opens its own windows.

EDIT: These shouldn't make any difference in performance except for the overhead of process creation and initialization.

The most important thing: it should't matter; if you are worrying about this you might actually want to keep Java running instead of launching it hundreds of times.