Fallow documentation

Find the code you can delete, merge, or refactor in a TypeScript or JavaScript project. Fallow analyzes code and styles statically for free, and Fallow Cloud, the optional paid product, shows what ran in production.

Fallow shows you which code in a TypeScript or JavaScript project you can delete, merge, or refactor. It is codebase intelligence: one command reads your whole module graph and reports what it finds.

The static layer finds:

• unused code
• duplication
• complexity hotspots
• architecture drift
• styling drift from your design system
• feature-flag branches

To learn which code executed in production, add the optional runtime layer.

Start here

1. 1

   Run fallow without installing

   npx fallow

   The first run needs no config.

2. 2

   Read the results

   One pass reports dead code, duplication, and complexity. For styling drift, run fallow audit or fallow health --css.

3. 3

   Go deeper

   npx fallow dead-code
   npx fallow dupes
   npx fallow health
   npx fallow fix --dry-run

What fallow helps you do

Pick your workflow

Understand the two layers

Static analysis tells you which code is connected to which. Production data from Fallow Cloud tells you which code actually ran. fallow health shows both.

Static analysis vs production data

Learn how the two layers differ before you set up runtime collection.

See also