Kotlin HTTP Client Libraries
HTTP client libraries for Kotlin work in both JVM and Android environments. OkHttp provides Java interoperability, Ktor Client offers Kotlin-native implementation, and Retrofit delivers type-safe API definitions. They feature asynchronous processing with coroutines and suspend functions.
GitHub Star Comparison
| No | Name | GitHub Stars | Description | Trend | License | Type | Official Site |
|---|---|---|---|---|---|---|---|
| 1 | OkHttp | - | High-performance HTTP client for Kotlin/Java. Developed by Square and officially recommended for Android. Built-in HTTP/2 support, connection pooling, GZIP compression, response caching, and automatic recovery from network failures. Good compatibility with Kotlin coroutines, optimized for modern async processing. | Maintains position as de facto standard HTTP client in Kotlin/Android development in 2025. First choice in modern Kotlin development through integration with Kotlin coroutines and suspend function support. Essential for microservices and mobile application development. | Apache 2.0 | High-performance | Official |
| 2 | Ktor Client | - | JetBrains-developed HTTP client supporting Kotlin multiplatform. Native Kotlin coroutines support, multiple engine compatibility (OkHttp, Apache, Curl, etc.). Enables common code across JVM, Android, JavaScript, Native platforms. Intuitive API design with DSL format. | Growing as important choice for Kotlin multiplatform development in 2025. Particularly enabling cross-platform development with single codebase in combination with Kotlin Native and Kotlin/JS. Provides continuous development and stability through JetBrains support. | Apache 2.0 | Multiplatform | Official |
| 3 | Retrofit | - | Type-safe HTTP client for Kotlin. Automatically generates HTTP client implementation from interfaces through annotation-based declarative API definition. Kotlin coroutines and suspend function support. JSON processing integrated with Moshi and Gson. | Maintains important position in Kotlin REST API development in 2025. Expanding adoption in both Android development and server-side Kotlin. Continuously chosen for large-scale API projects through improved development efficiency via type safety and code generation. | Apache 2.0 | Annotation-based | Official |
| 4 | Fuel | - | HTTP networking library designed specifically for Kotlin. Idiomatic Kotlin API, extension function utilization, coroutines support. Provides simple and readable syntax, RxJava support, and testing assistance features. Achieves intuitive development experience leveraging Kotlin language characteristics. | Continues use by Kotlin enthusiasts in specific projects in 2025. Holds value for small to medium-scale projects emphasizing simplicity and learning purposes, but new adoption limited due to enrichment of OkHttp and Ktor Client. Supported by developers seeking Kotlin-native development experience. | MIT | Kotlin-idiomatic | Official |