List of code validation tools

JSON Validator


Validates a JSON string against RFC 4627 (The application/json media type for JavaScript Object Notation) and against the JavaScript language specification. You can configure the validator to be lenient or strict.

  • Validates your JSON string/file against RFC 4627 in either strict or lenient mode
  • Validates your JSON string/file against the JavaScript specification
  • Supports copy-paste or file upload

HTML Validator


Validates the HTML string/file for well-formedness and compliance with w3c standards. It tries to make use of the doctype declaration to evaluate the document structrue but will resort to best practice if unmatched. The validator will report on missing or invalid attributes, unknown tags, unclosed tags and more.

  • Validates your HTML string/file using the doctype if possible or the 'best practices' if not
  • Checks for invalid tags, missing or invalid attributes, unclosed markeup and much more
  • Supports copy-paste or file upload

XML Validator (XSD)


Validates the XML string/file against the specified XSD string/file. XSD files are "XML Schemas" that describe the structure of a XML document. The validator checks for well-formedness first, meaning that your XML file must be parsable using a DOM/SAX parser. Only then does it validate your XML against the XML Schema. The validator will report fatal errors, non-fatal errors and warnings.

  • Validates your XML string/file using the provided XSD string/file
  • Supports copy-paste or file upload

XPath Tester


Executes an XPath query against an XML file. This online XPath tester will output the actual matched XML content along with the XML item type (Element, Text, CData, Attribute, etc.). Each match is displayed on a single line and this allows you also extract a subset of data if desired. XPath 2.0/3.0 compatible.

  • XPath 2.0/3.0 compatible
  • Supports XML namespaces
  • Extensive support of XPath functions
  • Reports the item type of the matched XML parts
  • Supports copy-paste or file upload

Credit Card Number Generator & Validator


Validates credit card numbers and also generates fake credit card numbers for all major brands. Obviously these number are for testing purposes and will not work with a payment processor. Also contains a full documentation and example of the Luhn algorithm used to validate most credit cards (Mod 10).

  • Validates credit card numbers
  • List of all card number formats per card issuer
  • Random credit card number generator for all major brands
  • Luhn algorithm explained

Regular Expression Tester


This regular expression tester will highlight every match in the original string so that you know exactly where a match occurs. It can be configured to be case-insensitive, work in multi-line mode and perform global matches. It also supports string replacements through with groups. It runs against a Java engine.

  • Highlights all matches in the original string
  • Supports the DOTALL flag; i.e. the dot metacharacter matches everything including line breaks
  • Supports case-insensitive, multiline and global flags
  • Extensive list of examples and regular expression recipes
  • Supports string replacements

Java Regular Expression Tester


This free Java regular expression tester lets you test your regular expressions against any entry of your choice and clearly highlights all matches. It is based on the Pattern class of Java 8.0.

  • Based on Java Pattern Class (Java 8.0)
  • Highlights all matches in the original string and shows extensive group details
  • Supports Java Pattern Flags (dotall, multiline, unix lines, etc.)
  • Extensive list of examples and regular expression recipes
  • Supports string replacements

Cron Expression Generator - Quartz


Generate a quartz cron expression with an easy to use online interface. Convert a cron expression into a readable text that clearly explains when it will execute, and visualize the next execution dates of your cron expression.

  • Convert a cron expression to text
  • Generate cron expression using simple user interface
  • Show next run time of cron expression
  • Preview most commonly used cron expression examples