Markdown Horizontal Rule

Matches a Markdown horizontal rule — three or more dashes, asterisks, or underscores on a line.

✓ Markdown parsers✓ Section detection✓ Document structure analysis

Risk

Test String

5 matches

---
***
___
- - -
* * *

^^— ^ — start of string (or line in multiline mode)

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

[…]Character class […]— Matches any single character listed in this set

\s*space— \s — whitespace (space, tab, newline…) — repeated zero or more times (greedy) · * — zero or more times (greedy)

\1\1— \1 — escaped character '1'

\s*space— \s — whitespace (space, tab, newline…) — repeated zero or more times (greedy) · * — zero or more times (greedy)

\1\1— \1 — escaped character '1'

(?:…)*Non-capturing group— Non-capturing group — groups without capturing (no index assigned) — repeated zero or more times (greedy) · * — zero or more times (greedy)

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

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

\1\1— \1 — escaped character '1'

$$— $ — end of string (or line in multiline mode)

Pattern: 29 charsInput: 23 chars

100% client-side · private

✓ Valid Examples

---
***
___
- - -
* * *

✗ Invalid Examples

--
**
not a rule
--- text

Usage & Integration

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

Node / Edge

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

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

Python

from regexto_validators import validate

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

Go

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

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

PHP

use RegexTo\Validators\Validator;

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

Rust

use regexto_validators::validate;

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