java -jar cfr-0.152.jar app.jar --outputdir ./decompiled --caseinsensitivefs true

java -jar fernflower.jar app.jar ./output

java -jar procyon-decompiler-0.6.0.jar app.jar -o ./src

jar tf app.jar | head -20 If you see classes named a/a.class , b/b.class , it is likely obfuscated. End of report.