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CalcHive

Validators

Validate JSON, XML, YAML, emails, URLs, credit cards, and more.

7 free tools available

Catching data errors early saves hours of debugging later. Our free online validation tools help you verify the correctness of JSON, email addresses, URLs, credit card numbers, JWT tokens, and other commonly used data formats. Each validator provides clear, actionable error messages that point you directly to the problem, so you can fix issues quickly and confidently.

Developers, QA engineers, and technical writers use these tools throughout the development lifecycle. Validate API response payloads during integration testing, check configuration file syntax before deployment, or verify that user-facing input patterns work correctly. All validation runs in your browser with no server round-trip, providing instant feedback as you type. These tools are a natural complement to your IDE's built-in checks and your CI/CD pipeline's automated tests.

JSON Validator
Popular
Validate and debug JSON syntax
Email Address Validator
Validate email address format
URL Validator
Validate URL format and structure
Credit Card Number Validator
Validate card numbers with Luhn check
YAML Validator
Validate and debug YAML syntax
JSON Schema Validator
New
Validate JSON data against a JSON Schema
Docker Compose Validator
New
Validate Docker Compose files for issues

Frequently Asked Questions

Why is data validation important in software development?▾
Data validation ensures that input data conforms to expected formats, types, and constraints before it is processed by your application. Proper validation prevents bugs, security vulnerabilities (like injection attacks), data corruption, and unexpected crashes. Validating data at every boundary, including user input, API responses, and file imports, is a fundamental best practice in software engineering.
What types of data can I validate with these tools?▾
Our validator tools cover the most commonly validated data formats in web development and system administration. You can validate JSON syntax, check email address formats, verify URL structures, validate credit card numbers using the Luhn algorithm, test JWT tokens, and more. Each tool provides detailed error messages that pinpoint exactly where validation fails.
How detailed are the validation error messages?▾
Our validators are designed to be as helpful as possible. When validation fails, you receive specific error messages indicating the exact location and nature of the problem. For structured formats like JSON, the tool highlights the line and character position of the syntax error. This makes it fast to identify and fix issues in your data.
Can I validate data against a custom schema?▾
Some of our validators support schema-based validation. For example, the JSON validator can check your data against a JSON Schema to verify not just syntax but also structure, required fields, data types, and value constraints. Check individual tool descriptions for schema validation support and capabilities.
Is my data kept private during validation?▾
Yes. All validation is performed locally in your browser. Your data is never transmitted to any server or stored anywhere. This means you can safely validate sensitive data such as API keys, configuration files with credentials, and personal information without any privacy concerns.