fscan: Find dead code in your Flutter project from the command line

Your Flutter project probably has more dead code than you think.

Dart's analyzer is great at catching type errors. It won't tell you that

lib/features/onboarding/legacy_screen.dart hasn't been imported since March,

or that assets/images/old_logo.png is still in your pubspec but never rendered.

I built fscan to solve this. It's a CLI tool written in Go that performs

static dead-code analysis across your entire Flutter/Dart project.

What it catches

• 
  Unused files — walks the import graph from your entry points, flags orphans


• 
  Unused assets — cross-references pubspec.yaml with actual usage in code


• 
  Unused public API — classes, functions, and widgets with no external callers


• 
  Unused routes — supports auto_route, go_router, and Navigator named routes


• 
  Maybe-unused methods — owner-class-aware matching to minimize false positives

Framework-aware

Flutter requires you to declare build(), initState(), dispose(), and

createState() — but you never call them directly. fscan skips all framework

lifecycle methods and @override annotations.

Generated file handling

.g.dart, .gen.dart, .gr.dart, .freezed.dart files are excluded from

unused-file detection. But they're still read as reference sources — so your

flutter_gen typed accessors and freezed models count as "used."

Owner-class-aware method analysis

A method named load() in BookService is tracked separately from load() in

UserService. No cross-class false positives from common method names.

Same-file self-reference detection

A public method called only within the same file (e.g., called in an event handler

above its declaration) is correctly marked as used.

Install

  brew install beobeodev/tap/fscan

  # or

  npm install -g @beobeodev/fscan

  # or

  go install github.com/beobeodev/fscan@latest

Run

  fscan scan /path/to/your/flutter/project

GitHub: https://github.com/beobeodev/fscan

Two severity levels

• Errors = high confidence, safe to delete


• Warnings = may be intentional (public API, dynamic routing) — review first