Fonsitor vs Kotzilla

Honest comparison -- when to choose each

Side by side

Both are built for Kotlin developers. The philosophy and cost model differ.

Feature Fonsitor Kotzilla
Price Free (open source) Free trial; paid from $49/mo
Target platform KMP: Android, iOS, Desktop, Server KMP: Android, iOS, Desktop, Web (JS/WASM)
Self-hosted Yes -- full self-hosted option No -- cloud only
DI framework integration Framework-agnostic Deep Koin integration (auto instrumentation)
Crash reporting Yes -- exceptions, stack traces, breadcrumbs Yes -- including iOS via PLCrashReporter (beta)
Performance monitoring Basic timing metrics ANR, slow components, startup P50/P95, screen ranking
Compose performance Manual event tracking Automatic Compose event visibility
AI-powered insights No Contextual AI prompts, AI-native analysis
Dashboard Self-hosted web UI Cloud dashboard with health metrics
SDK size overhead Lightweight (~50 KB) Moderate (Koin instrumentation layer)
Setup complexity Single Gradle dependency Gradle plugin + Koin config
Data ownership Full -- self-host, export anytime Cloud-managed by Kotzilla
Enterprise customers Indie / small teams Canal+, TotalEnergies, Volkswagen, Decathlon
Open source Yes No (proprietary)

Different tools, different strengths

The right choice depends on your budget, scale, and DI framework.

Choose Fonsitor when...

  • You want free, open-source error monitoring with no event caps
  • Data ownership and self-hosting are non-negotiable
  • You use any DI framework (Koin, Hilt, Kodein, or none)
  • A minimal SDK footprint matters for your app size budget
  • Your needs are focused on crash and error tracking
  • You prefer simplicity -- one dependency, works out of the box

Choose Kotzilla when...

  • You use Koin and want automatic DI instrumentation
  • You need deep Compose performance profiling (ANR, slow screens)
  • AI-powered insights and contextual analysis are valuable to your team
  • You need a managed cloud dashboard with enterprise SLAs
  • Startup performance (P50/P95 tracking) is a priority
  • You want iOS crash reporting alongside Android in one SDK

Kotlin error monitoring. Free. Open source.

Add Fonsitor to your KMP project with a single Gradle dependency.