Gradle Kotlin DSL Converter

A powerful tool to simplify the migration from Gradle's Groovy DSL to Kotlin DSL for Android and other Gradle projects.

Visit https://gradlekotlinconverter.app/ to use the converter.

Overview

This tool helps you migrate Gradle build scripts from Groovy DSL to Kotlin DSL. It automates the repetitive mechanical changes so you can focus on the parts that actually need manual attention.

It works with Android projects as well as pure JVM, Kotlin, and other Gradle builds. Think of it like Android Studio's Java → Kotlin converter — a powerful starting point rather than a perfect one-shot solution.

Features

• Converts Groovy Gradle scripts to Kotlin DSL
• Handles the most common syntax and idiomatic changes
• Supports Android, JVM, Kotlin, and general Gradle projects
• Adds helpful migration warnings for deprecated AGP APIs
• Works great as a first step (like the Java → Kotlin converter)

Getting Started

Web Interface

Visit the online converter — no setup required.

Local CLI

cd web
pnpm install

pnpm cli build.gradle
pnpm cli build.gradle > build.gradle.kts

Kotlin Script

kotlinc -script kotlin/gradlekotlinconverter.kts build.gradle
# or
./kotlin/gradlekotlinconverter.kts build.gradle

The Kotlin script has full feature and test parity with the TypeScript version.

Developing the project

cd web
pnpm install
pnpm test

Tests are a mix of focused unit tests and full-file golden fixtures in web/app/fixtures/golden/. The web/ implementation is the primary one and includes extra features like AGP migration warnings.

Supported Transformations

The converter handles the most common Groovy-to-Kotlin DSL changes. Here are some of the most frequently used transformations:

Description	Before	After
Strings	'kotlin-android'	"kotlin-android"
Variables	def appcompat = "1.0.0"	val appcompat = "1.0.0"
Apply plugins	apply plugin: "kotlin-kapt"	apply(plugin = "kotlin-kapt")
Dependencies	implementation ":epoxy"	implementation(":epoxy")
Maven repositories	maven { url "https://jitpack.io" }	maven("https://jitpack.io")
SDK versions (legacy)	compileSdkVersion 28	compileSdk = 28
SDK versions (modern)	compileSdk 36	compileSdk = 36
Version code / name	versionCode 4	versionCode = 4
Build types	debuggable true	isDebuggable = true
ProGuard	proguardFiles getDefault...	setProguardFiles(listOf(getDefault...))
Source compatibility	sourceCompatibility = "1.8"	sourceCompatibility = JavaVersion.VERSION_1_8
Includes	include ":app", ":diffutils"	include(":app", ":diffutils")
Signing configs	signingConfigs { debug { ... } }	signingConfigs { register("debug") { ... } }
Build types	buildTypes { debug { ... } }	buildTypes { named("debug") { ... } }
Kotlin dependencies	"org.jetbrains.kotlin:kotlin-stdlib:$v"	kotlin("stdlib")
Plugin blocks	Multiple apply(plugin = ...)	plugins { id(...) ... }
Extras	ext.kotlin_version = '2.1.20'	extra["kotlin_version"] = "2.1.20"

The converter also supports many modern Gradle patterns, including:

• Version catalogs, platform() dependencies, and includeBuild
• fileTree(mapOf(...)) and artifacts { add(...) }
• buildFeatures, testOptions, and Kotlin compiler options
• Modernization of legacy *SdkVersion declarations
• Helpful AGP migration warnings (variantFilter, RenderScript, density splits, etc.)

See the golden fixtures and web/app/logic.ts for the complete set of rules and realistic before/after examples.

The tool works on both .gradle and .kts files. Even if you paste just a dependency line like implementation '...', it will correctly add parentheses and quotes.

Limitations

The converter is a best-effort tool (similar to Android Studio's Java → Kotlin converter). It will not perfectly handle every case:

• Complex custom Groovy logic, helper methods in buildSrc, or heavy metaprogramming
• Some ext { } blocks containing closures (the tool inserts // TODO comments for manual review)
• Certain legacy or removed AGP/Gradle features that require larger architectural changes (the tool adds // TODO(AGP) notes where relevant)
• Every third-party plugin's custom DSL extensions

Always review the output, run a Gradle sync, and test your build. For tricky cases, the golden fixtures and focused regression tests document current behavior.

Issue Tracking

Found a bug? Have an idea for an improvement? Feel free to add an issue.