Markdown Bold

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

✓ Markdown parsers✓ Chat message formatting✓ Rich text editors

Safe

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

Usage & Integration

Validate Markdown Bold natively in your backend or frontend without copying regex strings.

Node / Edge

import { validate } from '@regexto/validators';

validate('markdown-bold', '...');

Python

from regexto_validators import validate

validate("markdown-bold", "...")

Go

import "github.com/regex-to/validators-go"

valid, err := validators.Validate("markdown-bold", "...")

PHP

use RegexTo\Validators\Validator;

Validator::validate('markdown-bold', '...');

Rust

use regexto_validators::validate;

let is_valid = validate("markdown-bold", "...").unwrap();