Regex Tester

Test and debug regular expressions with real-time matching, syntax highlighting, and detailed pattern explanations.

Regular Expression Pattern

Test Text

Flags

Active flags: /\b\w+@\w+\.\w+\b/g

Preset Patterns

Highlighted Text

Hello world! My email is john.doe@example.com You can also reach me at jane.smith@company.org Invalid emails: test@, @domain.com, user@domain

Matches (0)

No matches found

Pattern Explanation

• \b - Word boundary
• \w - Word character (alphanumeric + underscore)
• . - Any character (except newline)
• + - One or more occurrences

Features

Real-time Validation

Instantly validate your regex patterns and see syntax errors

Match Highlighting

Visual highlighting of all matches in your test text

Pattern Explanation

Understand what each part of your regex pattern does

Preset Patterns

Common regex patterns for emails, URLs, phone numbers, and more

Group Capturing

See captured groups and their positions in matches

Easy Copy

Copy patterns, matches, and results with one click

Common Use Cases

Data Validation

  • • Email address validation
  • • Phone number formatting
  • • Credit card number validation
  • • Password strength checking
  • • URL validation

Text Processing

  • • Find and replace operations
  • • Text parsing and extraction
  • • Log file analysis
  • • Code refactoring
  • • Data cleaning

Frequently Asked Questions

What are regex flags?

Flags modify how the regex pattern behaves. Common flags include 'g' (global - find all matches), 'i' (ignore case), 'm' (multiline), 's' (dotAll), 'u' (unicode), and 'y' (sticky).

How do I escape special characters?

Use a backslash (\) before special characters to treat them literally. For example, \. matches a literal dot, while . matches any character.

What are capture groups?

Parentheses () create capture groups that extract specific parts of a match. You can reference these groups later or see their values in the results.

How do I match the start or end of a string?

Use ^ to match the start of a string or line (with multiline flag), and $ to match the end. For example, ^hello matches strings that start with "hello".

Ready to Master Regular Expressions?

Practice with our comprehensive regex tester. Test your patterns, understand the syntax, and improve your text processing skills with real-time feedback.