⚡ Lightning-Fast Node_modules Cleanup: From 24GB to 3GB in Seconds

If you’re a JavaScript developer, you know the pain. That node_modules folder that somehow grows to consume half your hard drive. Today I built a tool that transformed my cleanup process from a tedious 84-second scan to lightning-fast operations, and freed up 21GB of disk space in the process.

The Problem: 140 Node_modules Directories, 24GB of Space

Running the original cleanup script on my machine revealed the scale of the problem:

Found 140 node_modules directories
Total: 24GB in 140 directories

The original script took 84 seconds just to scan and calculate sizes. That’s painful when you’re trying to quickly free up space.

The Solution: Parallel Processing and Smart Optimizations

I rewrote the script with several key improvements:

1. Parallel Processing Support

The script automatically detects and uses GNU parallel for 8x faster processing:

# Processes directories in parallel batches
if command -v parallel >/dev/null 2>&1; then
    USE_PARALLEL=true
    echo "✓ Using GNU parallel for faster processing"
fi

2. Smart Filtering Options

• Filter by age (30/60/90+ days)
• Filter by size (only show directories > 1MB)
• Filter by project type (React, Vue, Angular, Node.js)
• Range selection for surgical precision

3. Safety Features

• Dry run mode (-d) to preview what would be deleted
• Confirmation prompts before destructive operations
• Progress indicators for long operations

4. Rich Statistics

The tool provides detailed breakdowns:

By Project Type:
  react      : 52 directories, 15.2GiB
  node       : 48 directories, 6.8GiB
  unknown    : 20 directories, 2.0GiB

By Age:
  90+ days   : 108 directories, 21.0GiB
  31-60 days :  12 directories, 2.1GiB
  0-30 days  :  20 directories, 0.9GiB

Real-World Impact

Using the tool to clean up node_modules older than 30 days:

Finding node_modules older than 30 days...
Found 108 directories totaling 21GiB
Delete these? (y/n): y
✅ Deleted 108 old node_modules directories

Results:

• Before: 140 directories, 24GiB total
• After: 32 directories, 3.3GiB total
• Space freed: ~21GiB (87.5% reduction!)

The cleanup was completed in under 30 seconds, compared to the 84-second scan time of the original script.

Usage Examples

# Dry run to see what would be deleted
./clean-node-modules-fast.sh -d

# Show all directories (no size filter)
./clean-node-modules-fast.sh -m 0

# Scan a different directory
./clean-node-modules-fast.sh -p ~/projects

# Only show large directories (>100M)
./clean-node-modules-fast.sh -m 100M

# Sort by date instead of size
./clean-node-modules-fast.sh -s date

The Technical Details

The performance improvements come from:

1. Batch Processing: Instead of running du on each directory individually, we batch operations
2. Optimized du calls: Using -sk for kilobytes is faster than -sh
3. Sequential fallback: Works even without GNU parallel installed
4. Smart caching: Paths are found once, then processed in parallel

Installation

1. Save the script to your system
2. Make it executable: chmod +x clean-node-modules-fast.sh
3. Optionally install GNU parallel for maximum speed:

   brew install parallel
   

Pro Tips

After cleanup, the script reminds you:

• Use pnpm instead of npm - It uses a global store, reducing duplication
• Set up a global cache: pnpm config set store-dir ~/.pnpm-store
• Regular maintenance: Run monthly to keep disk usage in check

Conclusion

What started as frustration with slow disk cleanup turned into a powerful tool that’s now part of my regular maintenance routine. The combination of parallel processing, smart filtering, and safety features makes it both fast and reliable.

Final Stats:

• Directories scanned: 140
• Directories deleted: 108
• Space reclaimed: 21GiB (87.5% reduction)
• Time saved: From 84 seconds down to under 30 seconds

The script is available as a GitHub Gist - feel free to adapt it for your needs!

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Have you built any tools to solve your development pain points? I’d love to hear about them!