Regular Expression Tester

Enter regular expression and text, quickly match and highlight results

12 uses | 5.0 rating

Regular Expression Configuration

/ /

Match Results

Not Matched
Match Count
0
Match Time
0 ms
Regex Validity
Not Validated

Please enter a regular expression and test text, then click "Execute Match"

Usage Instructions

1

Enter Regular Expression

Enter the pattern you want to match in the regular expression input box. Use the flag checkboxes to set matching options.

2

Enter Test Text

Enter the text content you want to match against in the test text box.

3

Execute Match

Click the "Execute Match" button, and the system will perform regular expression matching on the text.

4

View Results

After matching is complete, you can view match statistics, match details, and highlighted match results.

Regular Expression Basics

What is a Regular Expression?

A regular expression is a pattern used to match character combinations in strings, commonly used for text search, replacement, and validation operations. It forms a rule to describe the characteristics of strings through the combination of special and ordinary characters.

Common Regex Flags

g
Global Match

Find all matches instead of stopping after the first match

i
Case Insensitive

Do not distinguish between uppercase and lowercase letters when matching

m
Multiline Mode

^ and $ match the start and end of each line

s
Dot All Mode

. matches any character including newlines

Common Regex Metacharacters

.

Matches any character except newlines

*

Matches the preceding character zero or more times

+

Matches the preceding character one or more times

?

Matches the preceding character zero or one time

^

Matches the start of the string

$

Matches the end of the string

Regex Optimization

  • Avoid greedy quantifiers, use the non-greedy forms *?, +?, ?? instead of *, +, ?
  • Use non-capturing groups (?:pattern) instead of capturing groups to reduce memory usage
  • Minimize backtracking, use specific character classes instead of wildcards
  • For complex matching, consider tokenization processing to avoid overly complex single expressions