Comparison

Fastify vs Ktor

On the evidence we track, Fastify leads this comparison with a composite score of 70/100. Scores are only directly comparable because these tools share a category; the full breakdown and every source is below.

Machine formatsMarkdownJSONGraphQLMarkdown is open. JSON and GraphQL need a free key.
★Fastify70
Ktor58
Score
vioscaleAI score
Fastify70 / 100high · 78%
Ktor58 / 100medium · 68%
Pricing
Free tier
Fastify✓
Ktor✓
Model
Price level
Fastifyfree
Ktorfree
Integrations
Count
Fastify28
Ktor–
Adoption
Dependent repos
Fastify16,712
Ktor484
Github stars
Fastify37,232
Ktor14,542
Activity
Commits last 30d
Fastify20
Ktor98
Release
Cadence days
Fastify4
Ktor27
History
Fastify20 items
License
Spdx
FastifyMIT
Language
Primary
FastifyJavaScript
KtorKotlin
Content
Faq
Fastify6 items

Capabilities

Feature-by-feature on the axes that matter for web frameworks. “-” means undocumented, not absent.

Core
Rendering model
Fastify-
Ktor-
File-based routing
Fastify✓
Ktor-
Language
FastifyJavaScript/TypeScript
KtorKotlin
Rendering
Server components
Fastify-
Ktor-
Streaming SSR
Fastify-
Ktor-
Fullstack
Built-in API / backend routes
Fastify✓
Ktor✓
DX
First-class TypeScript
Fastify✓
Ktor✗
Fast refresh / HMR
Fastify-
Ktor✓
Deployment
Edge runtime support
Fastify-
Ktor-

What each one is

The product in its own terms, so the numbers below have context.

Fastify

Leader

A Node.js web framework emphasizing fast request handling and low resource consumption while maintaining strong security, input validation, and developer experience.

Independently observed

Ktor

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

Independently observed

Pricing

List pricing as published by each vendor, with the date we read it. Always verify at the source before you buy.

Fastify

Leader
Open source
as of verify ↗

Ktor

Open sourceFree tier
as of verify ↗

Platform & deployment

Where each product runs and how it can be hosted. A dash means undocumented, not unsupported.

Platforms
Web
Fastify✓
Ktor✓
CLI
Fastify✓
Ktor✗
Deployment
Cloud / SaaS
Fastify✓
Ktor✓
Self-hosted
Fastify✗
Ktor✓
On-premise
Fastify✗
Ktor✓

Integrations

What each product connects to. Counts come from the vendor's own integration directory where one exists.

Fastify

Leader
40 total
  • Next.js
  • Apollo Server
  • Angular
  • PostgreSQL
  • MongoDB
  • Redis
  • Elasticsearch
  • Swagger/OpenAPI
  • WebSocket
  • JWT
  • Helmet
  • Sentry
  • RabbitMQ
  • CORS
  • CSRF
  • OAuth2
  • Kubernetes
  • Firebase
  • Mongoose
  • TypeORM
  • OAuth
  • GraphQL
  • Swagger
  • OpenAPI
  • +16 more
Independently observed

Ktor

Not documented yet.

Still deciding?

Fastify or Ktor: which one depends on you

A composite score cannot know your constraints. Describe them and both get re-weighted against what you actually need, with the evidence behind every position.

Free to run, no account needed to start. How the evaluation works

Comparison generated from independently-sourced facts. Every value links to its source and retrieval date. See the method.