New Framework for Kotlin Gains Popularity: What Developers Need to Know

New Kotlin Framework Gains Popularity: Overview and Prospects

The Kotlin ecosystem continues to develop rapidly, and 2025 has already seen significant growth in interest for one of the youngest but most promising frameworks — Ktor (a client-server framework from JetBrains) and in parallel — Compose Multiplatform for creating user interfaces. However, in recent months, Ktor has gained the biggest surge in popularity, actively displacing traditional solutions on Java and Node.js.

According to JetBrains surveys for Q1 2025, more than 38% of respondents using Kotlin have started or actively use Ktor in new projects. This is 12% more than a year earlier. Let's figure out why this framework deserves attention even from developers accustomed to Spring Boot or FastAPI.

What is Ktor and why has it become mainstream?

Ktor is an asynchronous framework for creating server applications and microservices in pure Kotlin. Its main features:

• Asynchrony out of the box — using coroutines and structured concurrency without unnecessary wrappers.
• Modularity — plug in only what you need: routing, serialization, authentication, WebSockets.
• Kotlin-first — full support for typing, nullable types, DSL for routes and plugins.
• Cross-platform — Ktor runs on JVM, Native (iOS, macOS, Linux) and JavaScript (browser).
• Performance — in TechEmpower benchmarks, Ktor shows speed comparable to Go and Rust, with the simplicity of Kotlin development.

Special interest in Ktor is fueled by the release of Ktor 3.0 at the end of 2024, which added built-in support for OpenAPI, improved gRPC handling, and Hot Reload for the server side.

How is Ktor changing the development approach?

Previously, the choice of a framework for Kotlin often came down to Spring Boot (heavy, lots of configuration, but huge community) or Micronaut. Ktor, however, offers a "light" start: a minimal server can be launched literally in 10 lines of code:

fun Application.module() {    routing {        get("/") {            call.respondText("Hello, Kotlin!", ContentType.Text.Plain)        }    }}

This is especially attractive for startups and small teams who want to quickly prototype APIs without overhead. Additionally, Ktor integrates perfectly with Compose Multiplatform: on one codebase you can write both the server and client applications for Android, iOS, Desktop, and Web.

Use cases and prospects

Among the well-known projects that switched to Ktor in 2025 are internal services of GitLab (for new Kotlin microservices), Cash App, and a number of fintech companies. Ktor is also actively used in IoT systems due to its low memory consumption.

Experts predict that by the end of 2025, Ktor will enter the top 5 most popular frameworks for microservices on JVM, surpassing Micronaut and Helidon. For Python developers who are looking at Kotlin, Ktor will become a natural analogue of FastAPI — just as fast, asynchronous, and with auto-documentation.