Regex Tester

The Regex Tester is an interactive regular expression testing tool that highlights matches in real-time as you type your pattern and test string. It supports all JavaScript regex flags (global, case-insensitive, multiline, dotAll, Unicode, sticky) and displays detailed match results with index positions and capture groups.

Regular expressions are a powerful text pattern matching syntax used across virtually all programming languages. Our tester helps you build, debug, and validate regex patterns before integrating them into your codebase — saving time and preventing bugs.

Test regex patterns interactively:

1. Enter your regular expression pattern between the / delimiters.
2. Set the desired flags (g, i, m, s, u, y) in the flags field.
3. Type or paste your test string in the text area below.
4. Matches are highlighted in real-time with their index positions and capture groups.

Regex testing accelerates development across many domains:

• Form Validation: Test email, phone number, and URL validation patterns before implementing them in forms.
• Data Extraction: Build patterns to extract specific data from log files, HTML, or structured text.
• Search & Replace: Develop complex find-and-replace patterns for code refactoring or text processing.
• Input Sanitization: Create patterns to validate and sanitize user input for security and data integrity.