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Lanterna

Lanterna

Illuminate your app's performance. One command to capture, analyze, and report — no Xcode or Android Studio required.
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Why Lanterna?

Lanterna is a CLI-first, cross-platform performance profiler designed specifically for React Native and Expo apps. Think of it as Lighthouse for mobile apps — capture, analyze, and report performance metrics from a single terminal command.

Key Features

  • Cross-platform — Full support for both iOS and Android. iOS profiling powered by xcrun xctrace directly from the CLI, no Xcode GUI required.
  • Zero-config entry point — Works on any running app without code changes. Point it at a package name and go.
  • RN-aware weighted scoring — A 0-100 composite score calculated from 11 heuristics tuned for React Native: UI FPS, JS FPS, CPU usage, memory, frame drops, TTI, and more.
  • CI/CD ready — JSON export, baseline comparison with regression detection, and a GitHub Action for automated performance gates.
  • 6 report formats — Terminal, JSON, HTML, Markdown, Perfetto, and SpeedScope output to fit every workflow.

See It in Action

╭───────────────────────────────────────╮
│  lanterna v0.0.1                      │
│                                       │
│  Score: 72 / 100  Needs Work          │
│  ██████████████░░░░░░  72%            │
│                                       │
│  Device: Pixel 6 (android, emulator)  │
│  Duration: 10s                        │
├───────────────────────────────────────┤
│  UI FPS         57.3 fps    ████  95  │
│  JS FPS         48.2 fps    ███░  62  │
│  CPU Usage      35.1%       ███░  55  │
│  Memory         245 MB      ███░  78  │
│  Frame Drops    8.2%        ██░░  42  │
│  TTI            1.8s        ████  90  │
╰───────────────────────────────────────╯

Quick Install

Terminal window
bun add -g @lanternajs/cli
lanterna measure com.example.app