ESLint Config Validator
Validate ESLint configuration online for free. Detect invalid rule severity values, malformed overrides, and common config mistakes before lint execution in CI and local environments.
Paste your ESLint configuration to detect schema issues, invalid rule severity values, malformed overrides, and top-level config mistakes.
Why Use Our ESLint Config Validator?
Instant Validation
Our tool to validate ESLint config analyzes your content instantly in your browser. Validate ESLint Config files of any size with zero wait time — get detailed error reports with line numbers in milliseconds.
Secure & Private Processing
Your data never leaves your browser when you use our ESLint config validator online tool. Everything is processed locally using JavaScript, ensuring complete privacy and security for sensitive configuration data.
No File Size Limits
Validate large ESLint Config files without restrictions. Our free ESLint Config Validator handles any size input — from small configs to massive files with thousands of entries.
100% Free Forever
Use our ESLint Config Validator completely free with no limitations. No signup required, no hidden fees, no premium tiers, no ads — just unlimited, free validation whenever you need it. The best free ESLint config validator online available.
Common Use Cases for ESLint Config Validator
CI Lint Gate Validation
Catch invalid ESLint config values before they fail pull-request lint checks in CI.
Plugin Wiring Checks
Validate plugin and rule structures to reduce startup errors during eslint execution.
TypeScript Override Audits
Verify override file globs and rule blocks for TS/TSX folders in mixed codebases.
Rule Severity Consistency
Ensure rule severities use valid values and tuple forms to avoid runtime lint config errors.
Monorepo Config Reviews
Check shared lint configuration changes safely before merging workspace-wide updates.
Safer Lint Refactors
Refactor legacy .eslintrc files with fast validation feedback and warning diagnostics.
Understanding ESLint Config Validation
What is ESLint Config Validation?
ESLint Config validation is the process of checking ESLint project linting configuration files (.eslintrc) for syntax errors, structural issues, invalid values, duplicate keys, and specification compliance — helping you catch problems before deployment. ESLint Config is widely used for defining code-quality and style rules, parser behavior, plugin usage, and environment assumptions for JavaScript and TypeScript projects. Our free ESLint config validator online tool checks your content instantly in your browser. Whether you need to validate ESLint config for repository lint setup, monorepo package rules, CI lint pipelines, and language-specific override policies, our tool finds errors accurately and privately.
How Our ESLint Config Validator Works
- Input Your ESLint Config Content: Paste your ESLint Config content directly into the text area or upload a
.eslintrcfile from your device. Our ESLint config validator online tool accepts any ESLint Config input. - Instant Browser-Based Validation: Click the "Validate ESLint Config" button. Our tool analyzes your content entirely in your browser — no data is sent to any server, ensuring complete privacy.
- Review Detailed Error Reports: View a comprehensive list of errors with line numbers, descriptions, and severity levels. Fix issues with pinpoint accuracy using our clear error messages.
What Gets Validated
- Syntax Correctness: Checks for proper syntax including balanced brackets, correct string quoting, valid escape sequences, and proper key-value pair formatting.
- Data Types: Validates integers, floats, booleans, strings, datetimes, arrays, and inline tables conform to the ESLint Config specification.
- Structural Integrity: Detects duplicate keys, conflicting table definitions, invalid table headers, and malformed sections.
- Line-by-Line Reporting: Every error includes its exact line number and a clear description, making it easy to find and fix issues in your ESLint Config files.
Related Tools
JSON to YAML
Convert JSON to YAML format instantly - Free online JSON to YAML converter
XML to YAML
Convert XML to YAML format for configuration migration - Free online XML to YAML converter
CSV to YAML
Convert CSV spreadsheet data to YAML format - Free online CSV to YAML converter
TSV to YAML
Convert TSV tab-separated data to YAML format - Free online TSV to YAML converter
Frequently Asked Questions - ESLint Config Validator
A ESLint Config Validator is a tool that checks ESLint Config files for syntax errors, structural issues, invalid values, and specification compliance. Our ESLint config validator online tool processes everything in your browser — giving you instant error reports with line numbers and clear descriptions.
Our ESLint Config Validator detects syntax errors (missing brackets, incorrect quoting), structural issues (duplicate keys, conflicting table definitions), invalid data types (malformed numbers, dates, strings), invalid escape sequences, and specification violations. Each error includes its exact line number for easy debugging.
Absolutely! Your data is completely secure. All validation happens directly in your browser using JavaScript — no data is ever uploaded to any server. Your configuration files, secrets, and sensitive data never leave your device.
Yes, our ESLint Config Validator is 100% free with absolutely no hidden costs or limitations. There's no signup required, no premium tier, no usage limits, no file size restrictions, and no advertisements. Use it unlimited times for any project.
Yes! Our ESLint config validator online tool handles files of any size. Since all processing happens in your browser, performance depends on your device, but modern browsers handle even very large ESLint Config files efficiently.
It validates top-level ESLint config keys, rule severity syntax, env/globals typing, plugin arrays, extends structure, ignore patterns, and override block shape.
Yes. Static JS object exports are supported. Dynamic code and computed expressions are not executed; they are treated as unsupported for safety.
Yes. It is useful for checking shared config updates and override sections before applying them across multiple packages.