What is Regex to Code Generator?
Regular expressions are powerful pattern-matching tools used across virtually every programming language, but each language implements regex with its own syntax conventions, escape rules, and API patterns. Writing the same regex in JavaScript, Python, Go, Java, C#, PHP, or Ruby requires knowing how each language compiles patterns, which methods to call for matching versus finding, and how to handle capture groups. This tool eliminates that friction by taking a single regex pattern and generating complete, idiomatic code snippets for eight popular programming languages. Each snippet includes the necessary imports, pattern compilation, a test match, and a find-all operation, so you can copy and paste directly into your project without looking up language-specific documentation. The tool also validates your regex before generating code, catching syntax errors like unbalanced parentheses or invalid quantifiers before they cause runtime exceptions. An optional test string lets you verify that the pattern behaves as expected, with live match results displayed alongside the generated code.
How to Use
- Select your target programming language from the dropdown — JavaScript, TypeScript, Python, Go, Java, C#, PHP, or Ruby
- Enter your regular expression pattern in the input area — use standard regex syntax without language-specific delimiters
- Optionally enter a test string to verify the pattern matches as expected before generating code
- Click "Generate Code" to produce a complete, runnable code snippet with imports, pattern compilation, and match operations
- Copy the generated code into your project — the snippet includes both simple match checking and find-all operations
Why Use This Tool?
Tips & Best Practices
- The sample pattern demonstrates a common email validation regex — use it as a starting point and modify for your needs
- Always test your regex with both matching and non-matching strings to catch false positives before deploying
- Different languages have different regex feature sets — for example, lookbehind assertions are not supported in Go's RE2 engine
- In Python, use raw strings (r"...") to avoid double-escaping backslashes — the generated code handles this for you
- For complex patterns with many groups, consider using named capture groups (?P<name>...) for more readable code
Frequently Asked Questions
Which programming languages are supported?
JavaScript, TypeScript, Python, Go, Java, C#, PHP, and Ruby. Each language generates idiomatic code using its standard regex library — RegExp in JS, re module in Python, regexp package in Go, java.util.regex in Java, System.Text.RegularExpressions in C#, preg functions in PHP, and Regexp class in Ruby.
How are regex syntax differences handled across languages?
The tool generates language-appropriate code: Python uses raw strings (r"..."), Go uses backtick raw strings, C# uses verbatim strings (@"..."), and PHP wraps the pattern in delimiters ("/pattern/"). Each snippet uses the most natural syntax for its language to minimize escaping issues.
When should I NOT use generated regex code?
Avoid using generated code for performance-critical hot paths without benchmarking — compiled regex objects should be reused rather than recreated on each call. Also, for complex validation logic, consider using a dedicated parser instead of regex, especially for nested structures like HTML or JSON.
What does the test result show?
If you provide a test string, the tool runs your pattern against it in the browser and displays whether it matches (boolean) and lists all found matches. This helps you verify the pattern works as expected before copying the generated code into your project.
Does the tool support regex flags like case-insensitive matching?
The current version generates code with the pattern as-is. You can add flags manually after generation — for example, append "i" for case-insensitive matching in JavaScript (/pattern/i), or pass re.IGNORECASE in Python. The generated code provides a clear structure where flags can be easily added.
Is my regex pattern sent to a server?
No. All pattern validation, testing, and code generation happen entirely in your browser. Your regex patterns and test strings never leave your device, making this tool safe for use with proprietary patterns or sensitive data matching rules.
Real-world Examples
Email Validation in Python
Generate Python code for validating email addresses using a standard regex pattern.
^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$# Python
import re
pattern = r"^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$"
test_string = "user@example.com"
# Check if pattern matches
is_match = re.match(pattern, test_string) is not None
print(is_match) # True
# Find all matches
matches = re.findall(pattern, test_string)
print(matches)URL Extraction in JavaScript
Generate JavaScript code to extract URLs from text using a regex pattern that matches http and https links.
https?://[\w\-]+(\.[\w\-]+)+[\w\-.,@?^=%&:/~+#]*
// JavaScript const pattern = /https?:\/\/[\w\-]+(\.[\w\-]+)+[\w\-.,@?^=%&:/~+#]*/g; const testString = "Visit https://example.com/page for more info"; // Find all matches const matches = testString.match(pattern); console.log(matches); // ["https://example.com/page"]