Text & Code Tools

Regex Tester

Test and debug regular expressions in real-time. See matches highlighted and capture groups extracted.

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Regex Cheat Sheet

Characters

  • . - Any character
  • \d - Digit [0-9]
  • \w - Word [a-zA-Z0-9_]
  • \s - Whitespace

Quantifiers

  • * - 0 or more
  • + - 1 or more
  • ? - 0 or 1
  • {n,m} - n to m times

Anchors

  • ^ - Start of string
  • $ - End of string
  • \b - Word boundary
  • \B - Non-boundary

Groups

  • (abc) - Capture group
  • (?:abc) - Non-capture
  • a|b - Or
  • [abc] - Character class

How to Use Regex Tester

  1. 1
    Enter Your Pattern

    Type your regular expression in the pattern field. Use the common patterns buttons for quick templates like email or phone validation.

  2. 2
    Configure Flags

    Select flags to modify matching behavior. Use "Global" to find all matches, "Case Insensitive" for flexible matching, or "Multiline" for line-based patterns.

  3. 3
    Test and Refine

    Enter test text to see matches highlighted in real-time. View capture groups in the details panel. Enable replace mode to test substitutions.

Why Use YaliKit's Regex Tester?

Real-Time Matching

See matches highlighted instantly as you type. No need to click buttons or wait for results.

Capture Group Details

View each capture group separately with clear labeling. Perfect for complex patterns with multiple groups.

Replace Mode

Test find-and-replace operations with group references ($1, $2). Preview the result before using in your code.

Built-in Cheat Sheet

Quick reference for common regex syntax. Character classes, quantifiers, anchors, and groups at a glance.

Frequently Asked Questions

What is a regular expression (regex)?
A regular expression is a sequence of characters that defines a search pattern. It's used for pattern matching within strings, such as finding email addresses, phone numbers, or validating input formats. Regex is supported in most programming languages.
How do I use capture groups in regex?
Capture groups are created by wrapping parts of your pattern in parentheses (). When a match is found, the text matching each group is extracted separately. Use $1, $2, etc. in the replace field to reference captured groups.
What do the different regex flags mean?
Common flags include: g (global) finds all matches instead of stopping at the first, i makes matching case-insensitive, m enables multiline mode where ^ and $ match line starts/ends, and s makes the dot (.) match newlines as well.

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