How do I test a regular expression online?

Paste your regex pattern into OneKit's Regex Tester and enter your test string below. Matches are highlighted in real time as you type. You can also set regex flags (global, case-insensitive, multiline) using the buttons provided.

What regex flags are supported?

OneKit's Regex Tester supports the standard JavaScript regex flags: g (global), i (case-insensitive), m (multiline), s (dotAll), and u (unicode).

🔍 Regex Tester

Test and debug regular expressions in real time. Matches are highlighted as you type - no page reload needed.

Regular Expression Pattern

/ / g

Flags

g — global i — ignore case m — multiline s — dot all

Test String

Enter a pattern to start

Match Preview

Matches will be highlighted here as you type.

How to use the Regex Tester

Type your regular expression in the Pattern field between the / delimiters.
Select the flags you need (global, ignore-case, multiline, dot-all).
Paste or type your test string - matches are highlighted instantly.
Scroll the Match Details section to see every match with its index position and capture groups.
Use the Quick Examples in the sidebar to load common patterns instantly.

Quick Examples

Regex Cheat Sheet

. Any character (except newline) \d Digit [0-9] \D Non-digit \w Word char [a-zA-Z0-9_] \W Non-word character \s Whitespace \b Word boundary ^ Start of string / line $ End of string / line * 0 or more (greedy) + 1 or more (greedy) ? 0 or 1 - optional *? 0 or more (lazy) {n,m} Between n and m times [abc] Character class [^abc] Negated class (abc) Capture group (?:abc) Non-capture group a|b a or b (?=…) Positive lookahead (?!…) Negative lookahead