Kover

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Introduction

Kover is a set of solutions for collecting test coverage of Kotlin code compiled for JVM and Android, maintained in the Kotlin organisation by JetBrains. The main entry point is the Kover Gradle plugin.

The plugin instruments tests, merges coverage across modules and Android build variants, and produces HTML, XML (JaCoCo-compatible) and binary reports. Verification rules can fail the build when line, branch or instruction coverage drops below thresholds, and filters exclude generated code or annotated classes. It understands Kotlin constructs such as inline functions and default arguments better than generic JVM tools.

In the quality loop Kover provides coverage gates for Kotlin builds.

The source code is at Kotlin/kotlinx-kover on GitHub under the Apache-2.0 licence, with about 1,600 stars; the most recent commit was on 26 October 2026.

Features

1. Gradle plugin: Simple setup for JVM and Android.
2. Multi-module merging: Aggregate coverage across projects.
3. Reports: HTML, XML and binary.
4. Verification rules: Fail builds on low coverage.
5. Filters: Exclude classes, packages and annotations.
6. Kotlin-aware: Handles Kotlin-specific bytecode.

Pros

1. Kotlin-first: Designed for Kotlin projects.
2. Free to use: Open source under the Apache-2.0 licence, so the core tool costs nothing to use.
3. Actively maintained: The repository had commits as recent as 26 October 2026.

Cons

1. Pre-1.0 versions: APIs have changed between releases.
2. JVM and Android only: Not for Kotlin/Native or JS.
3. Coverage is not quality: High numbers can still miss weak assertions.

Usage and Links (Example)

plugins { id("org.jetbrains.kotlinx.kover") version "0.9.11" }
kover { reports { verify { rule { minBound(80) } } } }

./gradlew koverHtmlReport koverVerify

Resources:

• Kover website

Pricing

Kover is free and open source under the Apache-2.0 licence.

Recommended for?

1. Kotlin JVM and Android teams wanting coverage gates.
2. Multi-module projects needing merged reports.

Conclusion

Kover is the natural coverage tool for Kotlin builds.

Upload its XML to Codecov or SonarQube for trends.

On CheckOps, Kover is filed under the Unit testing and Release & CI gates stages. Related tools listed here include JaCoCo, Codecov, Coveralls, Kotest, MockK and SonarQube. Before standardising on one, compare recent maintenance activity, the pricing model as your usage grows, and the integrations you rely on today. Information on this page was verified against the official website, documentation and repository on 11 November 2026.