# Just-in-Time Compilation

Runtime compilation of frequently used bytecode into native machine code.

## What is **Just-in-Time Compilation** in Java?

**Just-in-Time Compilation** — Runtime compilation of frequently used bytecode into native machine code.

```java
class Greeting {
    String message = "Hello, Java!";
}
```

Level: Master · [More Java terms at this level](https://www.ask-codey.com/glossary/subjects/java/master)

Updated: September 27, 2026

## In other subjects

- [Just-in-Time Compilation in JavaScript](https://www.ask-codey.com/glossary/just-in-time-compilation-javascript)

Source: https://www.ask-codey.com/glossary/just-in-time-compilation