Globbing at the speed of light

April 11, 2026 | 2 min read

When writing tools for developers, it’s often useful to write scripts that look at many files in a codebase.

The first choice in Javascript might be the glob package, but I quickly found out that it was too slow.

fast-glob is faster, but globby is even better because it supports a gitignore option.

Still, globbing in a large repo (~6 million LOC) was taking ~3-4 seconds on my 10-core M3 Macbook.

I discovered a neat trick though: you can use git ls-files (and picomatch) for really fast globbing.

Here’s what this looks like in Node:

import { spawn } from 'node:child_process';
import picomatch from 'picomatch';

const isMatch = picomatch(
  '{@types,apps,libs,tools,toolchain/**/*.{ts,tsx,js,jsx}}'
)

const paths = [];
const gitProcess = spawn('git', ['ls-files'], {
  stdio: ['ignore', 'pipe', 'inherit'],
});

let buffer = '';
for await (const chunk of gitProcess.stdout) {
  buffer += chunk.toString();
  const lines = buffer.split('\n');
  buffer = lines.pop() || '';
  lines.filter((line) => isMatch(line)).forEach((line) => paths.push(line));
}
if (buffer && isMatch(buffer)) {
  paths.push(buffer);
}

With this approach I’m able to get a relevant list of paths in milliseconds as opposed to seconds.

As long as you use git (and depending on the glob pattern) this may work for you as well. Always measure performance!