Java developer tools online

JSON to POJO, Maven↔Gradle, decompiler, stack trace colorizer, thread dump analyzer, bytecode viewer and more. No IDE required.

// 10tools in this category
json → javanew
generate java pojos or records from json
java decompilernew
decompile .class and .jar files back to java source
maven ↔ gradlenew
convert dependencies between maven and gradle dsl
properties ↔ yamlnew
convert spring boot application.properties ↔ application.yml
java stack tracenew
colorize and navigate java exceptions and stack traces
thread dump analyzernew
parse jstack output — thread states, deadlocks, blocking chains
java format stringnew
live preview of String.format and MessageFormat output
java formatternew
format java code with google-java-format — google or aosp style
bytecode viewernew
inspect jvm bytecode instructions from .class files with javap
quartz cronnew
parse quartz cron expressions with seconds and L/W/# syntax
// about

Java's ecosystem is sprawling — build systems, config formats, bytecode, stack traces, dependency notation, and logging formats all have their own quirks. This collection handles the common Java-specific tasks without opening an IDE: generate POJOs from JSON, convert dependency declarations between Maven and Gradle DSL, decode JVM bytecode, analyze stack traces and thread dumps, test format strings, and more.

// common use cases
  • Generate Java records or Lombok classes from a JSON API response schema
  • Convert Maven XML dependencies to Gradle Kotlin DSL when migrating a build
  • Analyze a thread dump from a hung production JVM to identify the blocking thread
  • Decompile a .class file from a third-party library to understand its behavior
// faq
Which tools require the Pro plan?
The Java decompiler (Vineflower), Java formatter (google-java-format), and bytecode viewer (javap) run on our servers and require a Pro plan. All other Java tools — POJO generator, Maven↔Gradle converter, stack trace analyzer, thread dump, format string tester, and Quartz cron — run entirely in your browser.
What Java version do the browser tools target?
The POJO/record generator supports Java 16+ records and Lombok. The Maven↔Gradle converter handles all current dependency scopes and common BOM imports. The format string tester covers all java.util.Formatter patterns through Java 21.
How accurate is the decompiler output?
The decompiler is powered by Vineflower — the same engine used in IntelliJ IDEA. It produces high-quality output that closely resembles the original source, including try-with-resources, lambdas, and switch expressions.
// other categories
convert10format5encode9generate4text7network2image2data6
// history
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