The only online tool that decompiles two Java web application archives and diffs the actual servlet source code. No installation required.
Drop old and new versions of your .war file into the upload areas.
Both WARs are unpacked and all .class files are decompiled to Java source.
View a file-by-file diff of every changed servlet, JSP, and configuration file.
A WAR (Web Application Archive) file is the standard packaging format for Java web applications. It is essentially a JAR file with a specific directory structure defined by the Java Servlet specification. Inside a WAR you will find:
WAR files package entire Java web applications including compiled servlets, JSP pages, static resources, and configuration. When deploying updates or auditing third-party web applications, you need to know exactly what changed in the code.
This tool decompiles both WAR files and produces a source-level diff, letting you see changes in servlet logic, configuration files like web.xml, and any embedded libraries. Use it for:
CLI tools like zipdiff can list changed files in WAR archives but cannot show code-level differences. Beyond Compare requires local installation. Generic online diff tools cannot handle WAR files. This is the only online tool that decompiles Java web application archives and shows a unified source diff of all servlets, classes, and configuration files.
Upload the original WAR on the left and the modified WAR on the right. Both files are decompiled to Java source code using FernFlower, then a unified diff is generated showing every changed class, JSP, and configuration file.
A WAR (Web Application Archive) file is a JAR file used to distribute Java web applications. It contains servlets, JSPs, HTML, JavaScript, CSS, web.xml, and often embedded JAR libraries in WEB-INF/lib.
WAR files are treated as JAR archives and decompiled using FernFlower with an automatic fallback to CFR. All .class files inside WEB-INF/classes and embedded JARs in WEB-INF/lib are decompiled.
Yes. The web.xml deployment descriptor and all other text-based configuration files are included in the diff. You can see changes to servlet mappings, filter configurations, security constraints, and other web.xml settings.
Yes. All embedded JARs in the WEB-INF/lib directory are decompiled along with the rest of the WAR. If a library was updated, you will see the decompiled source changes.
Yes, completely free. No registration or installation required.
Yes. Uploaded files are stored temporarily for decompilation and comparison, then automatically deleted. Files are never shared with third parties.