Skip to main content
Javalin logo

Javalin

Simple web framework for Java and Kotlin

A simple web framework for Java and Kotlin. Lightweight with minimal concepts to learn, running on Jetty with equivalent performance.

7K
GitHub Stars
none
TypeScript
easy
Learning Curve
4.5
DX Score
Visit Website → Documentation GitHub

Pricing

Model
free
Free Tier
Apache 2.0 licensed, fully open source

Features

  • ✓ Simple API
  • ✓ Java and Kotlin
  • ✓ Built on Jetty
  • ✓ OpenAPI/Swagger
  • ✓ WebSocket support
  • ✓ SSL/HTTP3 support
  • ✓ Flexible async
  • ✓ No annotations required
  • ✓ ReDoc integration

Pros

  • + Very simple to learn
  • + Lightweight
  • + Great for APIs
  • + OpenAPI built-in
  • + Kotlin-friendly

Cons

  • - Less features than Spring
  • - Smaller community
  • - Limited ecosystem
  • - Not for complex apps

Best For

startup indie hacker

Alternatives

Spring Boot Spring Boot Ktor Ktor
backend minimal kotlin java jetty