Pure Frontend · Regex to 10 Languages · Live Match Preview
Zero Dependencies · Works OfflineWhat Does the Regex to Code Converter Do?
Regular expressions are powerful for text processing, but different programming languages have different regex syntax and APIs. This tool converts your regex into complete, runnable code for JavaScript, Python, Java, Go, PHP, Rust, and 4 more languages — saving you from manually looking up docs and adjusting syntax. All conversion happens in your browser; your regex and test data are never uploaded.
Core Features
- 10 Language Support: JavaScript, Python, Java, Go, PHP, Rust, C#, Ruby, Swift, Kotlin
- Live Match Preview: Instant match results as you type regex and test text
- Flag Controls: g/i/m/s/u flags with auto-adaptation per language
- Batch Conversion: One regex per line, generate code for all at once
- Syntax Difference Handling: Auto Java double-escaping, Python raw strings, Go backticks, etc.
How to Use
Step 1: Enter regex — Type your regex pattern like \d{3}-\d{4} or click Load Example. Supports batch input (one per line).
Step 2: Set flags — Select g (global), i (case-insensitive), m (multiline), s (dotAll), u (unicode) as needed.
Step 3: Pick target language — Click a language button. Code is generated in real-time with regex definition, matching method, and test example.
Step 4: Copy or download — One-click copy or download as source file. Shortcuts: Ctrl+Enter to convert, Ctrl+Shift+C to copy.
Use Cases
Full-Stack Cross-Language Development
Validate email format in JavaScript on the frontend, then generate the same regex for Python or Java on the backend — ensuring consistent validation logic.
Technical Interview Prep
Quickly convert your familiar regex to the interview target language, avoiding mistakes from unfamiliar APIs.
Code Migration
When migrating a project to a new language, auto-convert regex with proper escaping and API calls, drastically reducing manual work.
Extended Knowledge
Regex Language Differences: JavaScript lacks lookbehind (pre-ES2018), Python's re module lacks atomic groups, Java requires double-escaping, Go uses RE2 (no backreferences). This tool flags incompatible features per language.
Best Practices: Validate regex with test text first, then convert. Use named capture groups for readability. Add error handling and performance testing in production to avoid ReDoS attacks.
FAQ
What programming languages are supported?
Currently supports JavaScript, Python, Java, Go, PHP, Rust, C#, Ruby, Swift, and Kotlin — 10 mainstream languages.
Can the generated code be used directly?
Yes. The generated code includes complete regex definition, matching method, and test example. Copy and paste into your project.
Does it support advanced regex features?
Supports common advanced features including capture groups, non-capturing groups, lookahead/lookbehind assertions, and named capture groups. Incompatible features are noted per language.
Will my regex data be uploaded?
No. All conversion happens in your browser. Your regex and test text are never sent to any server.
How are language-specific regex differences handled?
The tool auto-handles syntax differences: Java double-escaping, Python raw strings, Go backtick strings, etc. Generated code follows each language's best practices.
Can I batch convert multiple regexes?
Yes. Enter one regex per line and the tool generates code for all of them. Batch results can be downloaded as a file.
Feedback: dexshuang@google.com