Is a WAR file a virus?

A WAR is just a packaged web app. Like any code, it can contain something malicious, but it does nothing until a server deploys it. Open it in the JAR Viewer to see what it contains first.

Can I open a WAR file without Java?

Yes. Any ZIP tool can extract it, and the JAR Viewer shows the files and decompiles the classes in your browser.

Can I double-click a WAR file to run it?

Only an executable WAR (one with a Main-Class in its manifest) starts that way. A classic WAR needs a servlet container. ---

What Is a WAR File in Java? (WAR vs JAR vs EAR)

A Java WAR file is a ZIP-based Web Application Archive that a servlet container like Tomcat deploys. What's inside it, how it differs from a JAR, and how to open one.

What Is a WAR File in Java? (WAR vs JAR vs EAR)

Look Inside a WAR File Online

What's Inside a WAR File

WAR vs JAR vs EAR

How a WAR File Is Built

javax or jakarta: Which Server a WAR Needs

What You Can Do With a WAR File

FAQ

Summary