.* Regex Tester

Test and debug regular expressions live with real-time match highlighting. Supports flags, capture groups, and named groups. Free online regex tester — no signup needed.

/ /

g i m s

Test String

How to Use

Enter a pattern

Type your regular expression in the pattern field. Use the checkboxes to enable flags: g (global), i (ignore case), m (multiline), s (dotAll).

Add your test string

Paste or type the string you want to test in the Test String area. All matches are highlighted live as you type.

Inspect matches

See the total match count, each match with its position, and any capture groups. Copy the verified pattern to use in your project.

Frequently Asked Questions

What is a regular expression? +

A regular expression (regex) is a sequence of characters that defines a search pattern. They are used to match, find, or replace text in strings. For example, /\d+/ matches one or more digits.

What are regex flags and what do they do? +

Flags modify how a regex works. g (global) finds all matches, not just the first. i (ignore case) makes matching case-insensitive. m (multiline) makes ^ and $ match line boundaries. s (dotAll) makes . match newlines.

What are capture groups? +

Capture groups (...) let you extract specific parts of a match. For example, /(\d{4})-(\d{2})-(\d{2})/ matches a date and captures year, month, and day in separate groups. Named groups use (?<name>...) syntax.

Why does my regex not find all matches? +

Without the g (global) flag, the regex stops after the first match. Enable the g flag to find all occurrences. Also ensure you have not accidentally added anchors (^ or $) that restrict matching.

Is any data sent to a server? +

No. All regex processing runs entirely in your browser using JavaScript's built-in RegExp engine. Your pattern and test string never leave your device.

संपूर्ण गाइड: Regex Tester

Regex Tester क्या है?

Regular Expression (Regex) Tester patterns को real-time में test और debug करने का tool है। Regular expressions powerful pattern matching language हैं जो string validation, text extraction, और search-replace operations के लिए use होती हैं। बिना live testing के complex regex लिखना बहुत difficult होता है।

यह tool match highlighting, group capture visualization, और common regex patterns की library provide करता है। JavaScript, Python, PHP सभी में similar regex syntax होती है लेकिन कुछ differences होते हैं।

कैसे उपयोग करें

Regex pattern enter करें pattern field में (slashes के बिना)।
Flags select करें: g (global), i (case-insensitive), m (multiline)।
Test string paste करें — matches automatically highlight होंगे।
Groups panel check करें capture groups देखने के लिए।
Common patterns library से ready-made patterns use करें।

Pro Tips

^ और $ anchors use करें exact string matching के लिए, partial matching के लिए नहीं।
Greedy quantifiers (.*) को lazy (.*?) से replace करें unexpected matches avoid करने के लिए।
Named groups ((?<year>\d{4})) use करें code readability बढ़ाने के लिए।