</> aicodedetect

Java AI Code Detector

Paste a Java class or method to check whether it was likely written by an AI assistant or by a person. Free, instant, no sign-up.

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Signals that Java code was AI-generated

Java is verbose by design, and assistants tend to fill every slot the language offers. The result is code that is complete in a way a person writing against a deadline rarely bothers with. These are the Java patterns that come up most often.

  • Javadoc on every member. A /** ... */ block with @param and @return tags above each method, including one-line getters such as getName(), in a file where nothing else suggests the project publishes API docs.
  • The full boilerplate set. Getters and setters for every field, plus equals, hashCode and toString, on a class the task only needed to hold two values. Projects that use Lombok or records usually skip all of this.
  • A driver nobody asked for. A public static void main that builds sample objects and prints them with System.out.println, attached to a class that was supposed to be used from elsewhere.
  • Defensive checks everywhere. Objects.requireNonNull on each argument, IllegalArgumentException with tidy messages, and custom exception classes for a program that never catches them.
  • Uniform stream style. Every loop rewritten as stream().filter(...).map(...).collect(...), often with Optional return types, even where the rest of the codebase uses plain for loops.

Why Java produces false positives

Much of what looks generated in Java was generated, just not by an AI. IDEs write accessors, constructors and equals/hashCode pairs in a few keystrokes, and formatters such as google-java-format or a Checkstyle configuration make every file look the same. Coursework adds another layer: AP Computer Science A and most first-year university courses teach the same textbook class layout, so a student who follows the lecture closely writes something very close to what an assistant would. A high score on a plain data class is therefore much weaker than a high score on a method with real logic in it.

Checking a Java result fairly

Read the reasons, not only the percentage. If they point at Javadoc and accessors alone, ask whether the author's IDE or course template produces those. If they point at things a template does not produce, such as a demo main method, validation the assignment never mentioned, or a Java feature newer than the version the course uses, that is worth a closer look.

The most reliable follow-up is still a short conversation: ask the author why a field is final, what a particular stream does, or how they would add one more method. People who wrote the class answer that quickly.

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Frequently asked questions

Will getters and setters generated by my IDE be flagged as AI?

They can raise the score, because a full set of accessors is one of the patterns the analysis notices. IntelliJ IDEA, Eclipse and NetBeans all generate the same boilerplate on demand, so treat a result that rests mainly on getters, setters, equals and hashCode as weak evidence.

Should I paste the whole class or just one method?

A whole class, or at least a method with the fields it uses, gives the most to read. A single ten-line method from a standard algorithm carries very little style, and the answer will be uncertain.

Does it work for AP Computer Science A or university Java assignments?

Yes, it reads any Java you paste. Keep in mind that short, tightly specified assignments leave students little room for personal style, so a result there should start a conversation rather than settle one.

Does it understand modern Java such as records and switch expressions?

Yes. The snippet is read by a language model that knows current Java. Whether the code uses modern features is itself part of the picture, since it can be compared with the Java version the course or project actually targets.

Is my Java code stored?

No. The snippet goes to a third-party AI model provider (Groq, with Google Gemini as a fallback) for the analysis and the result comes straight back to you. We do not save the code or write it to our logs.