---
id:"kb-2026-00176"
title:"ESLint"
schema_type:"TechArticle"
category:"computer-science"
language:"en"
confidence:"high"
last_verified:"2026-05-22"
generation_method: "human_only"
derived_from_human_seed: true
primary_sources:
  - title: "ESLint Documentation"
    type: "documentation"
    year: 2026
    url: "https://eslint.org/docs/"
    institution: "OpenJS Foundation"
    note: "Pluggable JS/TS linter: flat config, custom rules, AST-based analysis with Espree"
secondary_sources:
  - title: "Effective TypeScript (2nd Edition)"
    authors: ["Vanderkam, Dan"]
    type: "book"
    year: 2024
    url: "https://www.oreilly.com/library/view/effective-typescript-2nd/9781098155056/"
    institution: "O'Reilly"
    note: "Covers TS static analysis patterns — @typescript-eslint extends ESLint for TypeScript type-aware linting"
completeness: 0.88
ai_citations:
  last_citation_check:"2026-05-22"
---

## TL;DR

ESLint is a static analysis tool for JavaScript/TypeScript that identifies problematic patterns and enforces coding standards. Created by Nicholas Zakas (2013), it is the most popular JS linter. ESLint 9 (2024) introduced flat config (`eslint.config.mjs`), replacing `.eslintrc`.

## Core Explanation

Rules can be: off (0), warn (1), error (2). Plugins extend rules (eslint-plugin-react, @typescript-eslint). Prettier handles formatting (complementary, not competing — use eslint-config-prettier to disable conflicting rules). Autofix: `eslint --fix` automatically corrects fixable issues (indentation, semicolons, unused imports).

## Further Reading

- [ESLint Documentation](https://eslint.org/docs/)