JAR File Won't Open? Fixes for Windows, Mac & Linux

Your JAR file won't open? Fix double-click doing nothing, the wrong app association, and missing Java — or open the JAR online with no install.

First: What Does "Open" Mean Here?

Option 1: Open the JAR Online (No Java, No Install)

Option 2: Install Java (To Run the JAR)

Option 3: Fix the File Association (Double-Click Does Nothing)

Still Won't Open? Rule Out a Corrupt File

Summary