Java 17 Online Compiler — Run Java 17 Programs Free
Compile and run Java 17 programs directly in your browser with our free online compiler. Java 17 is the recommended LTS version with powerful features like Records, Sealed Classes, Pattern Matching for instanceof, Text Blocks, and Switch Expressions. No installation required — start coding instantly.
Java 17 Key Features to Try
Records
Immutable data classes with auto-generated constructor, getters, equals, hashCode, and toString. Eliminate boilerplate code.
Sealed Classes
Restrict which classes can extend yours. Enables exhaustive pattern matching and better type safety.
Pattern Matching
Simplify instanceof checks with automatic type casting. No more redundant casts after type checking.
Text Blocks
Write multi-line strings with triple quotes. Perfect for JSON, SQL, and HTML embedded in Java code.
Switch Expressions
Use switch as an expression with arrow syntax. Cleaner, safer code with no fall-through bugs.
Performance
Improved garbage collection (ZGC, Shenandoah), faster startup, and lower memory footprint vs Java 8.
Frequently Asked Questions
What are the key features of Java 17?
Java 17 introduced Sealed Classes, Pattern Matching for instanceof, Records, Text Blocks (from Java 13), and Switch Expressions. It is the recommended LTS version for most projects.
Is Java 17 the latest LTS?
Java 17 was the latest LTS until Java 21 was released. Both are actively supported. Java 17 is widely adopted and recommended for production use.
What are Records in Java 17?
Records are immutable data classes that auto-generate constructor, getters, equals(), hashCode(), and toString(). Syntax: record Point(int x, int y) {} — much less boilerplate than regular classes.
What are Sealed Classes in Java 17?
Sealed classes restrict which other classes can extend them. Use "sealed" keyword with "permits" clause: sealed class Shape permits Circle, Rectangle {} — enables exhaustive pattern matching.
Should I use Java 17 for learning?
Yes! Java 17 is the ideal version for learning. It has all modern features, clean syntax improvements, and is an LTS release with long-term support until at least 2029.