This blog explains ESLint and Prettier, two popular tools developers use to enhance code quality and consistency. It clarifies their features and demonstrates how they can be effectively used in conjunction. Learn how to configure these tools to streamline your coding workflow and eliminate formatting conflicts and missed errors.

ESLint vs Prettier: Choosing the Best Tool for Your Code Quality

Why write clean code if others can't read it? What if your linter shows many warnings?

Consistent code is necessary for development. Often, developers discuss ESLint vs. Prettier. They aim to improve their code quality. Understanding their roles can save you time.

This blog breaks down ESLint and Prettier, covering their features and how they work together. You will learn which tool to use in different situations. We also explain how to configure them to cooperate.

Continue reading to simplify your coding workflow.

Why Code Quality Matters

Writing clean, consistent, and bug-free code isn’t just about style—it’s about maintaining code quality throughout the entire lifecycle of your application. Poorly formatted or unvalidated code leads to:

• Confusing pull requests

• Avoidable bugs

• Time wasted during build processes

• Broken functionality across environments

Static Code Analysis vs Code Formatting

Understanding the core difference between static code analysis tools like ESLint and code formatters like Prettier is foundational. Here's a quick breakdown:

ESLint: The Static Code Analysis Tool

ESLint is a powerful static code analysis tool designed to enforce coding standards, detect code issues, and prevent potential bugs. It parses your JavaScript code into an Abstract Syntax Tree (AST) and applies lint rules to spot code quality issues.

Key Features

• Detects unused variables, improper scoping, and more

• Enforces coding rules defined in the ESLint configuration file

• Supports ESLint plugins and custom parsers

• Integrates easily into code editors like Visual Studio Code

• Supports CLI: npm run lint or run eslint for manual checks

ESLint Rule Examples

Copy
1
2
3
4
5
6
7
{
  "rules": {
    "no-unused-vars": "error",
    "eqeqeq": "warn",
    "no-console": "warn"
  }
}

These ESLint rules ensure that code errors like instead of = or forgotten console.log statements don't make it to production.

Customization

You can create rules or extend eslint config and Prettier to adapt the tool to your development process. Use the ESLint plugin prettier to avoid formatting conflicts when combining the two tools.

Prettier: The Opinionated Code Formatter

Prettier is an opinionated code formatter that formats your code using predefined rules. Unlike ESLint, it doesn’t care about logic errors—it focuses solely on code formatting to maintain a consistent style.

What Prettier Does

• Normalizes spacing, indentations, semicolons, and wrapping code

• Operates on a JS file, JSON file, or other supported types

• Works across teams to remove subjective styling debates

• Can be run via the command line or integrated into your build process

Prettier Configuration File Example (.prettierrc)

Copy
1
2
3
4
5
{
  "semi": true,
  "singleQuote": true,
  "printWidth": 80
}

This prettier configuration file tells Prettier to enforce semicolons, single quotes, and a maximum line length of 80 characters.

Prettier and ESLint: Can They Work Together?

Yes—but with care. While both ESLint and Prettier can catch and fix style issues, they often overlap, which can cause conflicts between ESLint rules and formatting rules.

How to Combine ESLint and Prettier

You can integrate Prettier with ESLint using the following setup:

Copy
1
npm install --save-dev eslint prettier eslint-plugin-prettier eslint-config-prettier

Then update your ESLint configuration file:

Copy
1
2
3
4
5
6
{
  "extends": [
    "eslint:recommended",
    "plugin:prettier/recommended"
  ]
}

This tells ESLint to treat Prettier formatting issues as linting errors, avoiding duplicated efforts.

Mermaid Diagram: ESLint and Prettier Workflow

Key Differences: ESLint vs Prettier

Common Issues When Using Both ESLint and Prettier

• Conflicting rules (e.g., ESLint wants one style, Prettier another)

• Redundant rules around code settings like indentation

• Forgetting to install the ESLint plugin prettier

How to Avoid Conflicts

1. Use eslint-config-prettier to disable style-related ESLint rules

2. Always include eslint plugin,Prettierr and make Prettier run after ESLint

3. Adjust the configuration file to respect both tools

Practical Example: Configuring ESLint and Prettier Together

Folder Structure:

Copy
1
2
3
4
5
6
7
project-root/
│
├── .eslintrc.json
├── .prettierrc
├── package.json
└── src/
    └── app.js

package.json Scripts:

Copy
1
2
3
4
5
6
{
  "scripts": {
    "lint": "eslint src/**/*.js",
    "format": "prettier --write src/**/*.js"
  }
}

Run ESLint:

Copy
1
npm run lint

Format code:

Copy
1
npm run format

When to Choose ESLint vs Prettier

Final Thoughts

ESLint and Prettier are two essential tools that serve different but complementary purposes. One ensures your code is logically sound and error-free, and the other ensures every JS file follows the same code formatting style.

If you're serious about maintaining code quality, combining prettier and ESLint with proper configuration options is the way forward. Together, they help teams enforce coding standards, catch errors, and produce better code—every time you hit save in your code editor.