Ktor

Framework for building async server and client applications in Kotlin

Also known as
ktor

What is Ktor?

A Kotlin framework that uses asynchronous I/O and coroutines to build server-side, client-side, and microservice applications.

Independently observed

Ktor pricing

We don't have Ktor's full plan breakdown yet (its pricing page resisted automated reading). Here's what we could confirm. Always check live pricing for exact numbers.

What Ktor does

The capabilities that matter for web frameworks, normalised so it lines up with every alternative. “-” means we haven't confirmed it, not that it's missing.

Core
Rendering model
-
File-based routing
-
Language
Kotlin
Rendering
Server components
-
Streaming SSR
-
Fullstack
Built-in API / backend routes
DX
First-class TypeScript
Fast refresh / HMR
Deployment
Edge runtime support
-
Independently observed

Platform & deployment

Independently observed
Platforms
  • Web
Deployment
  • Cloud / SaaS
  • Self-hosted

Security & compliance

Known vulnerabilities: 0 (0 in the last 12 months) sourcea count reflects scale & disclosure, not quality

Ktor FAQ

Common questions about Ktor, answered from independent, dated evidence.

What is Ktor?

Ktor is an open-source framework for creating asynchronous server and client applications, from microservices to HTTP clients. Built on Kotlin and coroutines, it emphasizes simplicity, lightweight design, and extensibility. It is indexed under Web Frameworks.

Source: https://ktor.io/

Is Ktor free to use?

Ktor is open source, so it can be self-hosted and used at no licence cost. It is released under the Apache-2.0 licence. Pricing changes often, so verify at source before relying on it.

Source: https://ktor.io/

Is Ktor open source?

Yes. Ktor is published under the Apache-2.0 licence, a permissive licence that generally allows commercial use and modification. Licence terms can change between releases, so verify against the repository for the version you intend to use.

Source: https://github.com/ktorio/ktor

Ktor alternatives

Other web frameworks we track, ranked by the same independent score.

All Ktor alternatives, ranked →

Independent · unbought · dated

The vioscaleAI score: one lens on the evidence

Not user reviews and not a paid placement: a confidence-weighted blend of the independent signals below (adoption, activity, security posture, and more), which you can sort and re-weight yourself. Vendors can correct their listing but can never move their rank, and stars are weighted low as a vanity metric. It is one way to read the evidence for Ktor, not the verdict.

Balanced composite 59 / 100
medium · 68%
Signal contributions to the composite score
SignalScoreWeightContributionEvidence
Development activity630.127.5
Release cadence850.075.7
Dependent projects540.084.3
Capabilities460.083.8
Stars790.032.6
Security score460.052.4
Integrations00.050.0-
Security posture00.090.0-
Package downloads00.170.0-
Developer Q&A activity00.080.0-

Computed . Re-weight it by intent, or see the full method.

All data & sourcesshow ↓

Every value we hold, with its source, retrieval date, and confidence. This is the evidence behind the score: don't trust it, verify it.

Activity

AttributeValueEvidence
Commits last 30d98mediumsource · 2026-09-10 · 65%

Adoption

AttributeValueEvidence
Github stars14,520highsource · 2026-09-10 · 90%
Dependent repos1,648highsource · 2026-09-10 · 85%

Content

AttributeValueEvidence
Faq3 itemsmediumsource · 2026-09-10 · 72%

Features

AttributeValueEvidence
CapabilitiesLanguage: Kotlin · Api routes: Yes · Hot reload: Yes · Typescript first: Nomediumsource · 2026-09-10 · 60%

Language

AttributeValueEvidence
PrimaryKotlinhighsource · 2026-09-10 · 90%

License

AttributeValueEvidence
SpdxApache-2.0highsource · 2026-09-10 · 95%

Pricing

AttributeValueEvidence
Free tierYesmediumsource · 2026-08-13 · 60%
Modelopen_sourcemediumsource · 2026-08-13 · 60%
Price levelfreemediumsource · 2026-08-13 · 60%

Release

AttributeValueEvidence
Cadence days27mediumsource · 2026-09-10 · 70%
History20 itemsmediumsource · 2026-09-10 · 70%

Security

AttributeValueEvidence
Scorecard4.6highsource · 2026-09-10 · 90%
VulnerabilitiesCount: 0 · Source: https://advisories.ecosyste.ms/api/v1/advisories?ecosystem=maven&package_name=io.ktor%3Aktor-server-core&per_page=100 · Last 12m: 0highsource · 2026-09-10 · 90%
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