eslint_d

15.0.2 verified Sat Apr 25 auth: no javascript

eslint_d is a drop-in replacement for ESLint that runs linting in a persistent background daemon, drastically reducing startup latency (e.g., ~300ms to ~100ms per run on modern hardware). Version 15.0.2 requires Node.js >=22 and supports ESLint v4 through v10. It automatically starts, stops, and restarts the server, binds to parent/editor processes, and falls back to a bundled ESLint if a local one is missing. Key differentiators include environment variables for fine-tuning behavior, support for monorepos via `ESLINT_D_ROOT`, and a `--fix-to-stdout` option for editor integration. Unlike editor-built-in caches, it provides speed benefits to Vim, Neovim, Emacs, and Sublime Text, while Atom, VSCode, and WebStorm gain little due to their own caching.

Common errors

error Failed to start daemon: EADDRINUSE ↓

cause Another eslint_d instance or process is already using the default port.

fix

Run 'eslint_d stop' to kill the existing daemon, then restart.

error eslint_d: command not found ↓

cause eslint_d is not installed globally or not in PATH.

fix

Install globally: 'npm install -g eslint_d'. Or use 'npx eslint_d'.

error Error: No matching ESLint version found. ESLint v10.0.0 is not supported. ↓

cause eslint_d has a bundled ESLint that may not match the local project's version, or the installed ESLint version is out of support range (v4-v10).

fix

Ensure local eslint version is between 4 and 10. Update eslint or use a compatible version.

Warnings

breaking eslint_d v15 requires Node.js >=22. Older Node versions will not work. ↓

fix Upgrade Node.js to 22+ or use eslint_d v14.x if on earlier Node versions.

gotcha Editors like Atom, VSCode, and WebStorm already cache ESLint; using eslint_d may not improve performance and can cause conflicts. ↓

fix Do not configure eslint_d in those editors; stick with built-in ESLint support.

gotcha If ESLINT_D_PPID is not set and ESLINT_D_IDLE is 0, the daemon may never exit automatically, consuming resources. ↓

fix Set ESLINT_D_PPID to 'auto' or a specific PID, or set ESLINT_D_IDLE to a positive number of minutes.

deprecated CommonJS require() patterns for eslint_d are deprecated; it is ESM-only since v15. ↓

fix Use ES module imports if using as dependency (though primarily CLI). For CLI usage, use npx or global install.

Install

npm install eslint_d

yarn add eslint_d

pnpm add eslint_d

Imports

eslint_d CLI
wrong
```
eslint_d  # must be installed globally or via npx
```
correct
```
npx eslint_d --version
```
eslint_d is a CLI tool, not a library; use it directly in terminal or editor config.

Quickstart

Global installation of eslint_d and usage of its CLI commands for linting, daemon control, and fix-to-stdout.

npm install -g eslint_d
# Lint a file
eslint_d file.js
# Start daemon explicitly
eslint_d start
# Status
eslint_d status
# Fix to stdout (requires --stdin)
echo 'let x = 1' | eslint_d --stdin --fix-to-stdout
# Stop daemon
eslint_d stop