As a structuring tool widely employed in textual content, the horizontal line, or the horizontal rule as it’s often termed, plays a critical role in the realm of Markdown language. Specifically designed for brevity and ease of use, Markdown offers multiple means to implement this universally applicable feature.


  1. Overview of Markdown
  2. Implementation of Horizontal Lines
  3. Compatibility Across Different Markdown Flavors
  4. Conclusion

Overview of Markdown

Markdown is a plain-text formatting syntax first proposed by John Gruber, aimed at facilitating the authoring of web content. Due to its readability and simplicity, Markdown has increasingly been adopted for writing technical documentation, online forum discussions, and to create rich text using a plain text editor.

A typical Markdown document will contain a mixture of plain text and special characters to designate formatting cues, such as emphasis (bold, italic), headers, links, lists, and, concerned in this article: horizontal lines.

Implementation of Horizontal Lines

In Markdown, there are three ways to create a horizontal line:

  1. Using asterisks (*)
  2. Using hyphens (-)
  3. Using underscores (_)

Using Asterisks

To incorporate a horizontal line using asterisks, you need to type at least three asterisks on a new line.

Here is a practical implementation:



Using Hyphens

With hyphens, you can achieve the same effect. Like with asterisks, it requires the user to type at least three hyphens on a fresh line.

Example code:



Using Underscores

Lastly, underscores can be used to introduce a horizontal line. Similarly, at least three underscores must be added onto a new line.

Example code:



Compatibility Across Different Markdown Flavors

Markdown has been adopted and adapted into a variety of different “flavors”, each with slight variations on the original syntax. Some of these include GitHub Flavored Markdown (GFM), MultiMarkdown, and CommonMark to name a few.

It’s noteworthy that despite having these different flavors, the methods for creating a horizontal line (using asterisks, hyphens, and underscores) are uniformly recognized across all flavors. Whether you are writing a README on GitHub or a blog post with a MultiMarkdown converter, you can be assured of the compatibility of your Markdown code.


As we have seen, creating horizontal lines in Markdown is a straightforward task. By using either three asterisks, hyphens, or underscores, you can apply a break in your content, aiding in its organization and readability. With the uniform compatibility across different Markdown flavors, you can bring structure to your content, irrespective of your platform of choice.

In your journey to master Markdown, knowing how to effectively introduce and use horizontal rules is undoubtedly a valuable skill. By providing a visually pleasing segmentation to your text, horizontal lines will aid significantly in crafting content that is easily understandable and enjoyable to read.