0 ms
Pattern
/ /
Test String
Matches
No pattern yet
✦ AI Explanation
Enter a pattern and click "Explain" to see an explanation.
Token Breakdown
No tokens
✦ Regex Cheatsheet
Basic Patterns
. - Any character except newline
\d - Digit (0-9)
\D - Non-digit
\w - Word character (a-z, A-Z, 0-9, _)
\W - Non-word character
\s - Whitespace
\S - Non-whitespace
Anchors
^ - Start of string/line
$ - End of string/line
\b - Word boundary
\B - Non-word boundary
Quantifiers
* - Zero or more (greedy)
+ - One or more (greedy)
? - Zero or one
*? - Zero or more (lazy)
+? - One or more (lazy)
{n} - Exactly n times
{n,} - n or more times
{n,m} - Between n and m times
Groups & Alternation
(abc) - Capturing group
(?:abc) - Non-capturing group
a|b - Alternation (a or b)
Character Classes
[abc] - Any of a, b, or c
[^abc] - Not a, b, or c
[a-z] - Any lowercase letter
[A-Z] - Any uppercase letter
[0-9] - Any digit
Lookaround
(?=abc) - Positive lookahead
(?!abc) - Negative lookahead
(?<=abc) - Positive lookbehind
(? - Negative lookbehind
Flags
g - Global (find all matches)
i - Case-insensitive
m - Multiline (^ and $ match line boundaries)
s - Dotall (.) matches newlines
u - Unicode mode
Quick Reference

About Remaster Regex Tool

Remaster is a powerful online regex tool designed to help you create, test, and understand regular expressions with ease. Whether you're a regex novice or an experienced developer, this tool provides the features you need to work efficiently with regular expressions.

Key Features

  • Real-time Testing - See matches as you type your regex pattern
  • AI Assistance - Generate regex patterns from natural language descriptions and get explanations for existing patterns
  • Token Breakdown - Visualize and understand the components of your regex
  • Comprehensive Cheatsheet - Quick reference for common regex syntax
  • Multiple Modes - Support for matching, replacing, and splitting text
  • Group Highlighting - Visualize captured groups in your matches
  • Performance Metrics - See how fast your regex executes

How to Use

  1. Enter your regex pattern in the Pattern field
  2. Select any flags (g, m, i, s, u) as needed
  3. Type or paste text in the Test String area
  4. See matches highlighted in real-time
  5. Use the Explain button to get an AI-powered explanation of your regex
  6. Use the Generate button to create regex from natural language
  7. Explore the Token Breakdown and Regex Cheatsheet for help

Regex Tips

  • Use g flag for global matching (find all occurrences)
  • Use i flag for case-insensitive matching
  • Use m flag for multiline mode (^ and $ match line boundaries)
  • Use non-capturing groups (?:...) for better performance
  • Be careful with greedy quantifiers - use lazy versions *?, +? when needed

Created with ❤️ for developers everywhere. Happy regexing!