Mobile — Performance Profiling

Performance profiling on mobile splits into local instruments (Xcode Instruments, Android Studio Profiler, Perfetto) and field telemetry (MetricKit, Firebase Performance, Sentry, Emerge Tools). For crash data see Mobile — Crash Reporting. For app size analysis see Mobile — CI/CD & Build Tools.

iOS / Apple

• ★ Instruments — Xcode-shipped profiler; the primary tool. Templates: Time Profiler, Allocations, Leaks, Energy Log, Network, System Trace, Hangs, App Launch.
• Hangs Instrument — find main-thread hangs > 250ms.
• App Launch Instrument — pre-main, dyld, runtime init.
• ★ MetricKit — opt-in field metrics from real users (battery, hangs, launch, scroll); free; Apple-published.
• Xcode Organizer → Metrics — aggregated MetricKit data per release.
• Time Profiler — sampling CPU profiler.
• Allocations + Leaks — memory analysis.
• Network Instrument — request waterfall.
• os_signpost — annotate your code for profiling traces.

Android / Google

• ★ Android Studio Profiler — CPU, Memory, Energy, Network unified; live or recorded.
• ★ Perfetto — system-wide tracing tool; the modern replacement for systrace; great for finding off-main-thread issues, frame drops, binder calls. Free, Google.
• Macrobenchmark / Microbenchmark (Jetpack) — measure cold start, frame timing, Compose recomposition perf as part of CI.
• Baseline Profiles — AOT-compiled hotpath profiles to ship in your APK; measurable startup wins.
• systrace / atrace — older tracing; use Perfetto.
• strace / simpleperf — low-level CPU sampling.
• Layout Inspector recomposition counts — Compose-specific.

React Native

• Hermes Profiler — JS sampling profiler; load .cpuprofile in Chrome DevTools.
• Flashlight (BAM) — real-device perf measurement; FPS, CPU, memory; OSS.
• react-native-performance (Shopify) — perf timing primitives.
• Reactotron — basic instrumentation.

Flutter

• ★ Flutter DevTools — performance overlay, frame chart, CPU profiler, memory.
• Timeline.startSync / Timeline.timeSync — annotate code for traces.
• --profile mode — required for accurate measurements.

KMP / Compose Multiplatform

• Profile per-platform (Instruments on iOS, Android Studio Profiler on Android). KMP shared code shows up in both.

Field perf monitoring

• ★ Firebase Performance Monitoring — free; HTTP, screen render, custom traces.
• Sentry Performance — distributed tracing across mobile + backend; free OSS self-host or hosted free tier. See observability.
• Datadog RUM Mobile — paid.
• New Relic Mobile — paid.
• Embrace — mobile-native APM; paid.
• Bugsnag Performance — paid.
• Emerge Tools — performance + size + snapshots; paid.

App size

• ★ Emerge Tools — paid; the most-recommended tool for app-size analysis.
• App Size Tool (Apple) — Xcode-bundled.
• Android Studio APK Analyzer — built in.
• Bundletool size analysis — for AABs.
• react-native-bundle-visualizer, source-map-explorer for RN.

Battery / energy

• Energy Log Instrument (iOS) — find background CPU / radio activity.
• Battery Historian (Google) — Android energy analysis.
• MetricKit signposts for energy — appear in Xcode Organizer.

Pick this if…

• iOS primary: Instruments + MetricKit; ship Baseline Profiles' equivalent (no AOT-profile concept on iOS, but os_signpost + Hangs Instrument).
• Android primary: Android Studio Profiler + Perfetto + Baseline Profiles + Macrobenchmark in CI.
• RN: Hermes Profiler + Flashlight; field via Sentry Performance.
• Flutter: Flutter DevTools profile mode.
• Cross-platform field RUM: Sentry Performance or Firebase Performance.
• Need app size dashboards: Emerge Tools.