Kotej
Compare two JAR, WAR or EAR files
Did the new build really change only what it should? Drop the two archives and Kotej opens them in your browser and compares them entry by entry, including the archives nested inside them.
Free, no account, and nothing is uploaded: everything is compared in your browser.
What it does
- Nested archivesAn EAR with WARs and JARs inside is opened all the way down, so a changed library deep inside shows up.
- Configuration compared by meaningweb.xml, pom.xml, persistence.xml and JSON config are compared by structure; properties and text files line by line.
- Same or different at a glanceUnchanged classes are confirmed equal from the archive's checksums, so even large archives compare quickly.
- ZIP, JAR, WAR, EAR, AARAny ZIP-based archive works, including Android AARs and iOS IPAs.
How to use it
- Open Kotej and pick the two archives, one on each side.
- Expand the tree to see which entries differ or exist in only one build.
- Open a configuration file to see exactly what changed.
Questions
Does it decompile classes?
No. Classes are compared by their bytes, so you see which ones changed; the configuration and resources inside the archive are shown in full.
Can I compare an archive with an exploded folder?
Yes. Put the archive on one side and the folder on the other.
Why is my CI build different when nothing changed?
Usually timestamps in the manifest or generated files. Kotej shows exactly which entries differ, so you can tell a real change from build noise.
Are my files uploaded?
No. Kotej runs entirely in your browser: files are read on your device and compared there. Nothing is sent to a server, which is also why it works on confidential configuration, customer data and production logs.
Is it free?
Yes, free and with no account. There is also a native macOS app with the same engine, for comparing folders straight from Finder: Kotej on the Mac App Store.