🔍 Regex Tester
Test and debug regular expressions in real time
How the Regex Tester Works
- 1Enter your regular expression pattern in the regex field.
- 2Set flags (g for global, i for case-insensitive, m for multiline).
- 3Paste or type the test string to match against.
- 4Matches are highlighted in real time as you type.
- 5Capture groups, match positions, and explanations are displayed.
About Regex Tester
Test and debug regular expressions in real time. See matches highlighted, capture groups explained, and common patterns. Supports JavaScript regex syntax with flags.
Frequently Asked Questions
What is a regular expression?
A regular expression (regex) is a pattern that describes a set of strings. It's used in programming for searching, matching, and replacing text. For example, \d{3}-\d{4} matches phone numbers like 555-1234.
What do the flags g, i, and m mean?
g (global) finds all matches, not just the first. i (case-insensitive) treats A and a as equal. m (multiline) makes ^ and $ match line starts/ends, not just string start/end.
What regex syntax is supported?
This tester uses JavaScript regex syntax. Common tokens include: . (any char), \d (digit), \w (word char), \s (whitespace), * (0+), + (1+), ? (0-1), {} (quantifier), [] (character class), () (group).