Markdown Bold

Matches Markdown bold text wrapped in **double asterisks** or __double underscores__.

✓ Markdown parsers✓ Chat message formatting✓ Rich text editors

Test String

3 matches

**bold text**
__also bold__
**multi-word bold phrase**

(…)Group #1— Capturing group — captures matched text for reuse or extraction

\*\*— \* — escaped character '*'

||— | — alternation: matches expression on left OR right

__— '_' — literal character

(?!…)Negative lookahead (?!…)— Negative lookahead — asserts the following text does NOT match this pattern (zero-width)

\sspace— \s — whitespace (space, tab, newline…)

(…)Group #2— Capturing group — captures matched text for reuse or extraction

.+?.— . — matches any character except newline (unless 's' flag is set) — repeated one or more times (greedy) (lazy) · + — one or more times (greedy) (lazy)

(?<!…)Neg. lookbehind (?<!…)— Negative lookbehind — asserts what precedes does NOT match this pattern (zero-width)

\sspace— \s — whitespace (space, tab, newline…)

\1\1— \1 — escaped character '1'

Pattern: 29 charsInput: 54 chars

100% client-side · private

✓ Valid Examples

**bold text**
__also bold__
**multi-word bold phrase**

✗ Invalid Examples

*single asterisk*
** spaced **
plain text