XSD Regex Pattern Tester
XSD Pattern
Converted Pattern
^[A-Z]{2}[0-9]{3}$Test String
Result
AB123XSD Regex Syntax Reference
Character Classes
| . | Any character |
| [abc] | Match a, b, or c |
| [^abc] | Match anything except a, b, c |
| [a-z] | Character range (a to z) |
| \d | Digit (0-9) |
| \D | Non-digit |
| \s | Whitespace |
| \S | Non-whitespace |
| \p{L} | Unicode letter category(\p{L} (with 'u' flag)) |
| \p{N} | Unicode number category(\p{N} (with 'u' flag)) |
| \i | XML initial name character (XSD only, supported by xspattern) |
| \c | XML name character (XSD only, supported by xspattern) |
| [a-z-[aeiou]] | Character class subtraction (XSD only, supported by xspattern) |
Quantifiers
| a* | 0 or more |
| a+ | 1 or more |
| a? | 0 or 1 (optional) |
| a{n} | Exactly n times |
| a{n,} | n or more times |
| a{n,m} | Between n and m times |
| a*? | 0 or more (non-greedy) |
| a+? | 1 or more (non-greedy) |
Groups
| (abc) | Capturing group |
| (?:abc) | Non-capturing group |
| a|b | Match a or b |
Escaped Characters
| \t | Tab |
| \n | Newline |
| \r | Carriage return |
| \xhh | Hex character |
| \uhhhh | Unicode character |
Important Differences from JavaScript
| No anchors | XSD patterns match entire string by default (implicit ^ and $). xspattern handles this correctly. |
| No lookahead/lookbehind | XSD does not support (?=...), (?!...), (?<=...), (?<!...) |
| Unicode categories | XSD supports \p{L}, \p{N}, etc. xspattern supports Unicode 15.0. |
| XML name chars | XSD has \i and \c for XML name characters. xspattern supports these. |
| Character class subtraction | XSD supports [a-z-[aeiou]] syntax. xspattern fully supports this feature. |
Technical details
How the XSD Regex Pattern Tester Works
What the Tool Does
The XSD regex pattern tester allows you to test XML Schema Definition (XSD) regex patterns against sample text. XSD regex patterns differ from JavaScript regex in several important ways: they match the entire string by default (implicit ^ and $ anchors), don't support lookahead/lookbehind assertions, and have specific syntax rules for XML validation. This tool converts XSD patterns to JavaScript-compatible regex for testing while explaining the differences. It's useful for developers working with XML schemas, XSD validation, and XML data processing who need to test pattern constraints defined in XSD files.
Common Developer Use Cases
Developers use XSD pattern testers when working with XML Schema definitions that include regex constraints. XSD patterns are commonly used to validate XML element content, such as email addresses, dates, IDs, or custom formats. When defining XSD schemas, developers need to test their pattern constraints to ensure they correctly validate expected input while rejecting invalid data. The tool helps verify that patterns like [A-Z]2[0-9]3 correctly match formats like "AB123" but reject "ab123" or "ABC123". XSD pattern testers are essential for XML schema development, data validation, and ensuring compliance with XML standards.
Key Differences from JavaScript Regex
XSD regex patterns have several important differences from JavaScript regex. First, XSD patterns match the entire string by default, so you don't need to add ^ and $ anchors. The pattern [A-Z]2 automatically matches only strings that are exactly two uppercase letters. Second, XSD doesn't support lookahead ((?=...)) or lookbehind ((?<=...)) assertions. Third, XSD supports Unicode categories like \p{L} for letters and \p{N} for numbers, which require the Unicode flag in JavaScript. XSD also has special sequences like \i and \c for XML name characters that aren't available in JavaScript regex.
XSD Pattern Examples
Common XSD patterns include date formats like \d{4}-\d{2}-\d{2} for YYYY-MM-DD dates, identifier patterns like [A-Z]2[0-9]3 for two letters followed by three digits, and Unicode patterns like \p{L}+ for one or more Unicode letters. The tool shows how these patterns are converted to JavaScript regex and whether test strings match the entire pattern (full match) or only partially (partial match). Since XSD patterns must match the entire string, partial matches indicate the pattern doesn't fully validate the input.
Best Practices
When testing XSD patterns, remember that they validate entire strings, not substrings. A pattern like \d+ will only match strings that are entirely digits, not strings containing digits. Use character classes and quantifiers appropriately: [A-Za-z]+ matches one or more letters, while [A-Za-z]* matches zero or more letters. For XML validation, test both valid and invalid inputs to ensure your patterns correctly accept expected data while rejecting malformed input. The tool displays the converted JavaScript regex pattern so you can see how XSD patterns are translated for testing purposes.