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APIs · head to head

curl vs Kotlin Multiplatform

curl logo

curl

APIs

Command-line tool for transferring data using URLs with wide protocol support

From
Free
Rated
-
Full reviewWebsite
Kotlin Multiplatform logo

Kotlin Multiplatform

Mobile Development

JetBrains-funded technology for sharing Kotlin business logic across iOS, Android, web, desktop and server

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: curl open-source with no vendor pricing: curl is free and open-source under GPL 3.0; no subscription or licensing costs apply; Kotlin Multiplatform it shares logic, not UI, by default, so a team expecting a Flutter-style single UI codebase has to also adopt Compose Multiplatform, which is newer and less proven on iOS than on Android.
  • They diverge on capability: curl covers HTTP/HTTPS, Kotlin Multiplatform covers Shared Kotlin logic.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which curl and Kotlin Multiplatform actually diverge.

Attributes where curl and Kotlin Multiplatform differ
AttributecurlKotlin Multiplatform
Pricing modelopen-sourceOpen source, no licence fee
PlatformsLinux, MacOS, Windows, Unix, MobileiOS, Android, Windows, macOS, Linux, Web
CategoryAPIsMobile Development
Founded1997Unknown

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in curl

  • HTTP/HTTPS
  • FTP
  • Multiple protocols
  • Universal compatibility
  • Scripting tools
  • Linux support
  • MacOS support
  • Windows support

Only in Kotlin Multiplatform

  • Shared Kotlin logic
  • Native UI retained
  • Compose Multiplatform (optional)
  • IDE tooling
  • Gradle-based builds
  • Incremental adoption

What people use each for

The jobs each tool is most often brought in to do.

curl

  • API Developmentnot Kotlin Multiplatform
  • API Gatewaynot Kotlin Multiplatform
  • API Testingnot Kotlin Multiplatform
  • API Documentationnot Kotlin Multiplatform
  • Microservicesnot Kotlin Multiplatform

Kotlin Multiplatform

  • A company with existing separate native iOS and Android codebases wanting to stop duplicating business logic and networking codenot curl
  • A team that wants shared logic but is not willing to compromise on fully native UI per platformnot curl
  • An organisation already using Kotlin on the backend that wants to reuse the same models and validation on mobile clientsnot curl
  • A team evaluating Compose Multiplatform for UI sharing but wanting the option to fall back to native UI per screennot curl

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

curl

  • Open-source with no vendor pricing: curl is free and open-source under GPL 3.0; no subscription or licensing costs apply
  • Commercial support costs hidden: site references 'commercial support available' but pricing is not detailed or accessible from homepage
  • No SaaS model: curl is a command-line tool and library; costs are limited to optional commercial support contracts (pricing unknown)
  • Self-support burden: free software means customers rely on community forums or undisclosed commercial support pricing

Kotlin Multiplatform

  • It shares logic, not UI, by default, so a team expecting a Flutter-style single UI codebase has to also adopt Compose Multiplatform, which is newer and less proven on iOS than on Android.
  • iOS interop relies on Kotlin/Native compiling to a framework consumed from Swift, and debugging across that boundary is more friction than debugging pure Swift or pure Kotlin.
  • Because logic-sharing is the whole premise, teams still need genuine iOS and Android UI expertise on staff; it does not reduce the native skills bar the way a full cross-platform UI framework aims to.
  • Build times and tooling maturity for multiplatform Gradle projects lag behind single-platform Kotlin or Swift projects, and multiplatform-specific build errors are less well documented.
  • JetBrains funds it as part of the broader Kotlin investment, so its roadmap priority competes internally with IntelliJ, Android Studio and other JetBrains commitments rather than having dedicated headcount the way Flutter has at Google.

Pricing, plan by plan

curl

Free
  • Open SourceFree
    • Full curl functionality
    • Community support

Kotlin Multiplatform

Free
  • Kotlin MultiplatformFree
    • Apache 2.0 licensed, unlimited apps
    • IDE tooling in the free Android Studio and free-tier IntelliJ IDEA Community
    • No paid Kotlin Multiplatform edition exists

Which should you pick?

Choose curl if

  • You need http/https.
  • You want to start without paying.
  • You work on Linux, MacOS, Windows, Unix, Mobile.
  • You also want ftp.
curl review

Choose Kotlin Multiplatform if

  • You need shared kotlin logic.
  • You want to start without paying.
  • You work on iOS, Android, Windows, macOS, Linux, Web.
  • You also want native ui retained.
Kotlin Multiplatform review

Questions people ask

Is curl or Kotlin Multiplatform better?
Neither clearly leads. curl starts at Free and Kotlin Multiplatform at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, curl or Kotlin Multiplatform?
curl starts at Free and Kotlin Multiplatform at Free.
Does curl or Kotlin Multiplatform run on more platforms?
curl runs on Linux, MacOS, Windows, Unix, Mobile. Kotlin Multiplatform runs on iOS, Android, Windows, macOS, Linux, Web.
Can I use curl for free?
Both have a free tier, so you can try either at no cost before committing.
What is curl best used for?
curl is most often used for api development, api gateway, api testing, api documentation. Of those, api development and api gateway are not what Kotlin Multiplatform is typically brought in for.
What can curl do that Kotlin Multiplatform cannot?
curl covers HTTP/HTTPS, FTP, Multiple protocols, Universal compatibility. Kotlin Multiplatform covers Shared Kotlin logic, Native UI retained, Compose Multiplatform (optional), IDE tooling.

Answered from the vendors’ own pages

curl: How much does curl cost?

curl is free and open-source software under the GPL 3.0 license. There is no cost to download, use, or modify the software.

Source
Kotlin Multiplatform: Does Kotlin Multiplatform replace my native UI code?

Not by default. It shares business logic and data layers; UI stays native per platform unless you separately adopt Compose Multiplatform.

curl: Is commercial support available for curl?

Yes. The curl website references 'commercial support available,' but pricing and details are not disclosed on the homepage and require visiting the support page.

Source
Kotlin Multiplatform: Is there a paid version?

No. It is Apache 2.0 licensed and free, funded by JetBrains as part of the Kotlin project.

curl: Can I sponsor curl financially?

Yes. The curl website offers an option to 'Sponsor curl financially.' Visitors can donate to support curl development, but the donation link must be accessed through the site's support section.

Source
Kotlin Multiplatform: Do I need Compose Multiplatform to use it?

No, they are separate. You can share only logic and keep fully native UI on each platform indefinitely.

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