ESLint vs Biome: Which JavaScript Tool Should You Choose?

Modern JavaScript and TypeScript projects need more than a compiler and a package manager to stay maintainable. As applications grow, teams need automated checks for bugs, code quality, consistency, formatting, and architectural conventions.

For years, ESLint has been one of the most widely adopted solutions for JavaScript linting. It provides a highly configurable rule system, an extensive plugin ecosystem, and the flexibility to tailor linting to almost any development workflow.

Biome takes a different approach. Instead of focusing primarily on linting, it aims to provide a unified toolchain for modern web development, combining formatting, linting, import organization, and other developer tooling in a single high-performance application.

That creates an important question for teams starting a new application or modernizing an existing codebase:

Should you stay with ESLint, or is Biome now a better choice?

What Is ESLint?

ESLint is a configurable linter for JavaScript. It analyzes source code and identifies patterns that may indicate bugs, poor practices, or violations of a project's coding standards.

One of ESLint's biggest strengths is its extensibility. Projects can enable built-in rules and add third-party plugins, custom rules, shareable configurations, and parsers.

Modern ESLint uses the flat configuration system, typically through an eslint.config.js, .mjs, or related configuration file.

For example, a large React or Next.js application may use ESLint to enforce rules around unused variables, React-specific patterns, accessibility, imports, security practices, and organization-specific coding standards.

What Is Biome?

Biome is a modern toolchain designed for JavaScript and TypeScript projects. It provides formatting and linting while also supporting capabilities such as import organization.

Its main attraction is consolidation. Instead of assembling several developer tools around a JavaScript project, a team can use Biome for multiple code-quality tasks through a single CLI and configuration system.

Biome supports languages and file types commonly encountered in modern web projects, including JavaScript, TypeScript, JSX, TSX, JSON, CSS, GraphQL, and more.

Biome also provides migration tooling for existing ESLint configurations, although migration is not guaranteed to reproduce exactly the same behavior because Biome does not implement every ESLint rule or option identically.

ESLint vs Biome: The Fundamental Difference

The biggest difference is not simply speed.

It is philosophy.

Area	ESLint	Biome
Primary focus	Highly configurable linting	Unified web development toolchain
Linting	Yes	Yes
Formatting	Possible through integrations/tools	Built in
Import organization	Usually handled through rules/plugins	Built in
Plugin ecosystem	Very extensive	More controlled
Configuration flexibility	Very high	More opinionated
Migration from ESLint	Native ecosystem	Dedicated migration command
Type-aware linting	Available through ecosystem integrations	Available in Biome 2

1. Linting Capabilities

ESLint's core purpose is linting. Its rules can identify issues such as unused variables, questionable patterns, unreachable code, and project-specific conventions.

The important advantage is that teams can choose exactly which rules they want and how strictly they should be enforced.

For example, a company may configure one rule as an error, another as a warning, and disable another entirely. ESLint also supports third-party plugins that introduce additional rules and configurations.

Biome also provides a substantial linting system with recommended rules and its own rule organization.

Biome 2 expanded this further by introducing type-aware linting without requiring the TypeScript compiler.

Practical difference: ESLint gives teams an extremely broad ecosystem for specialized linting. Biome gives teams a more integrated linting experience inside a unified toolchain.

2. Formatting

This is where the two approaches become noticeably different.

ESLint is primarily a linter. Formatting is commonly handled alongside ESLint through tools such as Prettier or formatter-related integrations.

Biome includes a formatter as part of the toolchain.

For a project that previously used:

ESLint + Prettier + import sorting

Biome can potentially consolidate several of these responsibilities into one workflow.

Biome's formatter is designed to work across JavaScript, TypeScript, JSX, TSX, JSON, CSS, GraphQL, and other supported formats.

3. Plugin Ecosystem

This is one of ESLint's strongest advantages.

ESLint was designed to be extensible. Plugins can provide custom rules, configurations, processors, parsers, and even support for additional languages.

Imagine an enterprise frontend where the team has an internal coding policy that checks:

approved API clients
restricted imports
internal component usage
security-sensitive functions
specific accessibility conventions
company-specific naming patterns

ESLint can be extended to implement these requirements.

Biome has its own rule ecosystem and supports migration from several popular ESLint rule sources, but it does not attempt to reproduce the entire ESLint plugin ecosystem.

For highly customized linting, ESLint still has a major advantage.

4. Configuration Philosophy

ESLint intentionally gives developers a high degree of control.

A project can define which files are analyzed, which rules apply, which plugins are loaded, how parsers behave, and how different parts of the codebase are treated.

Modern ESLint's flat configuration system uses configuration objects and JavaScript modules, allowing configurations to be composed programmatically.

Biome uses a more centralized configuration model through biome.json or biome.jsonc.

This can make configuration easier to understand for teams that prefer convention over extensive customization.

The trade-off is straightforward:

ESLint gives you more knobs. Biome tries to give you fewer knobs that you need to manage.

5. Performance and Developer Experience

Biome is implemented as a high-performance toolchain and is designed to make formatting and linting fast enough to fit naturally into frequent developer workflows.

Its documentation positions it as a toolchain that can format, lint, and perform related tasks quickly, while its CLI provides commands such as biome check for combined workflows and biome ci for continuous integration.

That can be particularly useful when a repository contains thousands of JavaScript and TypeScript files and developers run checks repeatedly during development and CI.

However, performance should not be reduced to a single benchmark number.

A real project spends time reading files, parsing source code, resolving dependencies, running plugins, executing CI jobs, and interacting with editors. The practical benefit of Biome may therefore come not only from raw execution speed, but also from reducing the number of separate tools involved in the workflow.

6. ESLint and Biome in a Next.js Project

Consider a growing Next.js application with:

TypeScript
React components
API routes
shared UI components
automated CI checks
multiple developers
several thousand source files

With an ESLint-centered workflow, the project might combine ESLint with additional formatting and import-management tooling.

With Biome, the team can consolidate formatting, linting, and import organization into a more unified workflow.

For example, developers can use:

biome check --write

to format code, lint it, and organize imports according to the configured workflow. Biome also provides biome ci for CI environments.

The result can be a simpler developer experience, particularly for teams that do not require a large collection of specialized ESLint plugins.

7. Migrating from ESLint to Biome

Switching tools does not necessarily mean starting from zero.

Biome provides a dedicated migration command:

biome migrate eslint

It can read an ESLint configuration and attempt to translate its settings into Biome's configuration model.

Biome's migration tooling supports both legacy ESLint configurations and the modern flat configuration format.

But migration should be treated as a starting point rather than a perfect conversion.

For example, suppose an existing project relies on a specialized ESLint plugin with custom rule options. Biome may not provide an exact equivalent.

A sensible migration process is:

Audit the current ESLint configuration.
Identify which rules are genuinely important.
Run Biome's migration tooling.
Review migrated rules manually.
Compare lint results.
Run the application's test suite.
Update CI and editor integrations.
Remove obsolete tooling only after the new workflow is stable.

Biome itself notes that migration is best-effort and may not reproduce ESLint behavior exactly.

8. When ESLint Is the Better Choice

ESLint is usually the safer choice when customization and ecosystem compatibility are the highest priorities.

Choose ESLint when your project:

depends heavily on specialized ESLint plugins
has extensive custom linting rules
uses organization-specific linting conventions
requires a very specific existing ESLint configuration
already has a mature ESLint workflow that works well
needs integrations that are not available in Biome

For a large enterprise application with years of accumulated linting rules, replacing ESLint simply because another tool is newer may create unnecessary migration work.

9. When Biome Is the Better Choice

Biome becomes particularly attractive when simplicity and unified tooling are more important than maintaining a large plugin ecosystem.

Consider Biome when:

you are starting a new JavaScript or TypeScript project
you want formatting and linting in one tool
you want to reduce configuration overhead
you want a fast developer workflow
you want built-in import organization
your project does not depend on specialized ESLint plugins
you are comfortable with a more opinionated toolchain

For example, a startup creating a new TypeScript SaaS application may prefer Biome because developers can adopt one tool for several code-quality tasks instead of maintaining a collection of separate tools.

10. Can ESLint and Biome Work Together?

Yes.

Teams do not necessarily need to make an immediate all-or-nothing decision.

A migration can be gradual. For example, a team may introduce Biome for formatting while keeping ESLint for specialized linting rules.

However, teams should avoid creating overlapping responsibilities without a clear reason.

If both tools format the same files with different configuration rules, developers can end up with unnecessary conflicts.

A cleaner hybrid strategy is to define exactly which tool owns formatting and which tool owns specialized linting.

11. ESLint vs Biome: Which One Is Faster?

Biome is designed with performance as a major goal, and its architecture focuses on providing a fast unified developer toolchain.

But the better engineering question is not simply:

“Which one is faster?”

Instead ask:

“Which workflow gives our team the lowest friction while meeting our quality requirements?”

If a project requires ten specialized ESLint plugins, switching to Biome may not improve the overall developer experience even if individual operations are fast.

If a project mainly needs formatting, common lint rules, and import organization, consolidating those operations may provide a larger practical benefit.

12. A Practical Decision Framework

Project Situation	Recommended Direction
Large existing ESLint codebase	Usually stay with ESLint unless there is a measurable reason to migrate
New TypeScript application	Biome is worth evaluating
Heavy ESLint plugin usage	ESLint
Minimal configuration desired	Biome
Formatting + linting in one tool	Biome
Highly customized enterprise rules	ESLint
Gradual migration	ESLint + Biome can coexist with clearly separated responsibilities

ESLint vs Biome: The Real Trade-Off

The decision is less about choosing an outdated tool versus a modern tool.

ESLint is still extremely relevant because its extensibility solves problems that a unified toolchain cannot necessarily cover. Its plugin and configuration model makes it particularly valuable for organizations with specialized engineering policies.

Biome takes a different path: reduce toolchain fragmentation and provide common development tasks through one integrated system.

So the choice depends on what your project values most.

Choose ESLint for maximum ecosystem flexibility and customization.

Choose Biome for a streamlined, integrated JavaScript and TypeScript toolchain.

How Code-Ox Approaches Tooling Decisions

At Code-Ox, tooling decisions should be based on the application's actual requirements rather than simply choosing the newest technology.

For a new TypeScript or Next.js application, a unified toolchain such as Biome can simplify developer workflows and reduce configuration overhead.

For an established enterprise codebase with custom ESLint rules, plugins, and years of configuration, keeping ESLint may be the more practical engineering decision.

The important step is to evaluate the complete development workflow: developer experience, CI execution, plugin requirements, maintainability, team familiarity, and migration cost.

Final Verdict

ESLint and Biome solve overlapping problems, but they are designed around different priorities.

ESLint is the better fit when your team needs deep customization, a mature plugin ecosystem, or highly specialized linting rules.

Biome is compelling when you want a modern, integrated toolchain that brings formatting, linting, import organization, and related workflows together.

For a new project, Biome deserves serious consideration. For a mature ESLint-based application, migration should be justified by measurable benefits rather than technology trends.

The best tool is ultimately the one that keeps your codebase consistent without creating unnecessary friction for the people maintaining it.