Open .class Files Online (Java Class Viewer)

Open and inspect Java .class files online. View decompiled Java code, methods, packages, and metadata instantly.

What Is a .class File?

How to Open a .class File Online

What You See When You Open a .class File

Understanding the Decompiled Output

Inner Classes and Anonymous Classes

Class File Viewer vs Full JAR Decompiler

When Class Files Cannot Be Decompiled Cleanly

Class Files vs JAR Files

FAQ