jake kim

Posted on Apr 14

ESLint vs Biome 2026: Which JavaScript Linter Should You Choose?

#javascript #typescript #webdev #tooling

Originally published on dev-jake.blogspot.com | Korean version available

Introduction

When you start a new JavaScript project, what's the first thing you set up? That's right—a linter. It's essential for maintaining code quality and catching bugs early. But right now, developers face a choice between two compelling options: the battle-tested ESLint, and the performance-focused newcomer Biome.

Both have their merits, but what's the real difference? Let's break it down based on 2026 standards.

What is ESLint?
What is Biome?
Performance Comparison
Feature Comparison
Migration Guide
How to Choose
FAQ

What is ESLint?

ESLint is the de facto standard JavaScript linter, dating back to 2013. Used in almost every JavaScript project and one of the most downloaded tools in the npm ecosystem.

Strengths of ESLint

1. Overwhelming Community
After 12 years of development, community resources are massive. Search any ESLint error and you'll usually find an answer.

2. Plugin Ecosystem
Thousands of specialized plugins for React, Vue, TypeScript, Next.js, and more.

3. Fine-Grained Customization
Almost every rule can be individually toggled. Team standards can be reflected precisely.

4. Battle-Tested Stability
Meta, Google, Netflix all use it. Bug risk is minimal.

Weaknesses of ESLint

Performance is slow. On large projects, linting alone can take 10+ seconds. Bundle size is substantial (~50MB).

What is Biome?

Biome is an emerging JavaScript linter + formatter built in Rust, designed to solve ESLint's speed problem.

Strengths of Biome

1. Incredibly Fast
Built in Rust, it's 10-100x faster than ESLint. Large projects complete in milliseconds.

2. Small Bundle Size
ESLint is ~50MB, Biome is ~5-10MB. CI/CD times drop significantly.

3. Formatter Included
Linter + formatter are unified. No need to install Prettier separately.

4. Modern Technology
Built-in support for TypeScript, JSX, JSON, YAML.

Weaknesses of Biome

1. Smaller Community - Stack Overflow answers can be slower.

2. Limited Plugin Ecosystem - Customization is limited compared to ESLint.

3. Not Yet Mature - Not as battle-tested as ESLint.

Performance Comparison

Metric	ESLint	Biome
Linting Speed (1000 files)	8-15 seconds	0.5-1 second
Bundle Size	~50MB	~8MB
Memory Usage	200-400MB	50-100MB
Formatting Speed	Prettier required	Integrated

Biome is overwhelmingly faster — dramatic difference especially in CI/CD environments.

Feature Comparison

Feature	ESLint	Biome
Number of Rules	300+	150+
TypeScript Support	Plugin required	Built-in
JSX Support	Built-in	Built-in
Formatting	Prettier required	Integrated
Plugin System	Extremely rich	None
Customization	Fine-grained	Basic rules only

ESLint to Biome Migration

Step 1: Install Biome

npm install -D @biomejs/biome

Step 2: Create biome.json

{
  "linter": {
    "enabled": true,
    "rules": {
      "style": {
        "useAsConstAssertion": "error",
        "noVar": "error"
      }
    }
  },
  "formatter": {
    "enabled": true
  }
}

Step 3: Gradual Migration

Run both ESLint and Biome in parallel to verify differences before fully switching.

Warning: Verify your team's critical rules are all covered in Biome before committing.

How to Choose

Choose ESLint if:

Your team has complex, custom linting rules
You need specialized plugins (React, Vue, etc.)
Proven stability is your top priority

Choose Biome if:

Performance matters (large monorepos, CI/CD speed)
You prefer unified TypeScript + formatting
You want a simpler, modern toolchain

My Take

I choose based on project size:

Small (1-3 members): Biome. Speed and simplicity win.
Medium (4-10 members): ESLint if rules are complex, otherwise Biome.
Large: ESLint. It's insurance.

FAQ

Q: Is Biome really 100x faster?
On 1000 files, ESLint ~10s vs Biome ~0.5s. The difference is especially dramatic in watch mode.

Q: Will we lose important rules switching to Biome?
Biome has 150 rules; teams typically use 20-30. Most are covered.

Q: Can we use ESLint and Biome together?
Temporarily during migration, yes. Eventually choose one.

Q: Is Biome production-ready in 2026?
Absolutely. Many companies use it in production. Just verify your team's rules first.

Conclusion

ESLint is the proven king. Biome is the fast newcomer. Choose based on your team's actual needs.

Original post (Korean): ESLint vs Biome 2026: JavaScript 린터, 뭘 써야 할까?

April 2026 | dev-jake.blogspot.com | 5+ years frontend engineering

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