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Mobile Development · head to head

Kotlin Multiplatform vs Umami

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
Umami logo

Umami

Marketing

Open source, cookie-free web analytics you can self-host for the cost of a database

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: 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.; Umami there is no cohort analysis, retention curve, session replay or multi-touch attribution, so a marketing team that needs to justify channel spend will still buy a second tool and Umami becomes a supplementary dashboard.
  • They diverge on capability: Kotlin Multiplatform covers Shared Kotlin logic, Umami covers Cookie-free tracking.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

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

Attributes where Kotlin Multiplatform and Umami differ
AttributeKotlin MultiplatformUmami
Pricing modelOpen source, no licence feePer month by event count
PlatformsiOS, Android, Windows, macOS, Linux, WebWeb, Linux
CategoryMobile DevelopmentMarketing

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 Kotlin Multiplatform

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

Only in Umami

  • Cookie-free tracking
  • Self-hosting
  • Small tracking script
  • Custom events
  • Funnels and goals
  • Multi-site and teams
  • Public dashboards
  • API access

What people use each for

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

Kotlin Multiplatform

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

Umami

  • A developer who wants traffic numbers on a personal or client site without adding a consent bannernot Kotlin Multiplatform
  • An organisation whose legal or procurement team has ruled out sending visitor data to a US advertising companynot Kotlin Multiplatform
  • A high-traffic site where hosted analytics priced by pageview band has become expensive and self-hosting removes the ceiling entirelynot Kotlin Multiplatform
  • A team that wants analytics data in a database they already control so they can query and join it themselvesnot Kotlin Multiplatform

Where each one falls short

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

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.

Umami

  • There is no cohort analysis, retention curve, session replay or multi-touch attribution, so a marketing team that needs to justify channel spend will still buy a second tool and Umami becomes a supplementary dashboard.
  • Self-hosting is only free in licence terms; you own the database, the upgrades, the backups and the query performance at scale, and a busy site's events table grows quickly enough to need real attention.
  • Because it stores no persistent identifier, it cannot follow a user across devices or sessions in any meaningful way, which makes returning-visitor and lifetime-value questions unanswerable by design rather than by omission.
  • Cloud overage is billed per event beyond the plan allowance, so a traffic spike or a badly instrumented custom event can produce a bill materially above the $20 or $200 headline before anyone notices.
  • It is maintained by a small team, so the pace of new capability is modest and enterprise expectations such as SSO, granular role permissions and formal support agreements are limited compared with commercial analytics vendors.

Pricing, plan by plan

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

Umami

Free
  • Self-hostedFree
    • MIT licensed, no licence fee
    • No event limit imposed by the software
    • Unlimited websites and users
  • Cloud HobbyFree
    • Up to 100,000 events per month
    • 3 websites
    • 6 months data retention
  • Cloud Pro$20/month
    • Up to 1,000,000 events per month
    • Unlimited websites
    • Unlimited team members
  • Cloud Business$200/month
    • Up to 10,000,000 events per month
    • All Pro features
    • Higher volume overage rate

Which should you pick?

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

Choose Umami if

  • You need cookie-free tracking.
  • You want to start without paying.
  • You work on Web, Linux.
  • You also want self-hosting.
Umami review

Questions people ask

Is Kotlin Multiplatform or Umami better?
Neither clearly leads. Kotlin Multiplatform starts at Free and Umami at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Kotlin Multiplatform or Umami?
Kotlin Multiplatform starts at Free and Umami at Free.
Does Kotlin Multiplatform or Umami run on more platforms?
Kotlin Multiplatform runs on iOS, Android, Windows, macOS, Linux, Web. Umami runs on Web, Linux.
Can I use Kotlin Multiplatform for free?
Both have a free tier, so you can try either at no cost before committing.
What is Kotlin Multiplatform best used for?
Kotlin Multiplatform is most often used for a company with existing separate native ios and android codebases wanting to stop duplicating business logic and networking code, a team that wants shared logic but is not willing to compromise on fully native ui per platform, an organisation already using kotlin on the backend that wants to reuse the same models and validation on mobile clients, a team evaluating compose multiplatform for ui sharing but wanting the option to fall back to native ui per screen. Of those, a company with existing separate native ios and android codebases wanting to stop duplicating business logic and networking code and a team that wants shared logic but is not willing to compromise on fully native ui per platform are not what Umami is typically brought in for.
What can Kotlin Multiplatform do that Umami cannot?
Kotlin Multiplatform covers Shared Kotlin logic, Native UI retained, Compose Multiplatform (optional), IDE tooling. Umami covers Cookie-free tracking, Self-hosting, Small tracking script, Custom events.

Answered from the vendors’ own pages

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.

Umami: Is Umami really free?

Self-hosted, yes; it is MIT licensed with no event cap. You pay for the server and database. Umami Cloud has a free tier at 100,000 events a month and paid tiers from $20.

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.

Umami: Do I need a cookie consent banner?

For Umami analytics specifically, generally no, because it sets no cookies and stores no personal data. Other tags on your site may still require one.

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.

Umami: Can it replace Google Analytics?

For traffic, referrers and event counts, yes. For attribution modelling, audiences and advertising integration, no.

Umami: What does it need to run?

A container and a PostgreSQL or MySQL database. Most people deploy it on infrastructure they already pay for.

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