Gfm Markdown



Code

Renders local and remote URLs Granular access to remote origins Multiple markdown parsers Full control over the compiler options Themes (including GitHub theme) GitHub Flavored Markdown (GFM) Auto reload on file change Syntax highlighted code blocks Table of Contents (TOC) MathJax and Emoji support Mermaid diagrams support Remembers scroll position Markdown Content-Type detection URL detection. The most complete documentation/example is ' Markdown Cheatsheet ', and it illustrates that this element.

Overview

Nearly all Markdown applications support the basic syntax outlined in John Gruber’s original design document. There are minor variations and discrepancies between Markdown processors — those are noted inline wherever possible.

Headings

To create a heading, add number signs (#) in front of a word or phrase. The number of number signs you use should correspond to the heading level. For example, to create a heading level three (<h3>), use three number signs (e.g., ### My Header).

MarkdownHTMLRendered Output
# Heading level 1<h1>Heading level 1</h1>
## Heading level 2<h2>Heading level 2</h2>

Heading level 2

### Heading level 3<h3>Heading level 3</h3>

Heading level 3

#### Heading level 4<h4>Heading level 4</h4>

Heading level 4

##### Heading level 5<h5>Heading level 5</h5>
Heading level 5
###### Heading level 6<h6>Heading level 6</h6>
Heading level 6

Alternate Syntax

Gfm

Alternatively, on the line below the text, add any number of characters for heading level 1 or -- characters for heading level 2.

MarkdownHTMLRendered Output
Heading level 1
<h1>Heading level 1</h1>
Heading level 2
---------------
<h2>Heading level 2</h2>

Heading level 2

Heading Best Practices

Markdown applications don’t agree on how to handle a missing space between the number signs (#) and the heading name. For compatibility, always put a space between the number signs and the heading name.

✅ Do this❌ Don't do this
# Here's a Heading
#Here's a Heading

Paragraphs

To create paragraphs, use a blank line to separate one or more lines of text.

MarkdownHTMLRendered Output
I really like using Markdown.
I think I'll use it to format all of my documents from now on.
<p>I really like using Markdown.</p>
<p>I think I'll use it to format all of my documents from now on.</p>

I really like using Markdown.

I think I'll use it to format all of my documents from now on.

Paragraph Best Practices

Gfm Markdown Table

Unless the paragraph is in a list, don’t indent paragraphs with spaces or tabs.

✅ Do this❌ Don't do this
Don't put tabs or spaces in front of your paragraphs.
Keep lines left-aligned like this.
This can result in unexpected formatting problems.
Don't add tabs or spaces in front of paragraphs.

Line Breaks

To create a line break (<br>), end a line with two or more spaces, and then type return.

MarkdownHTMLRendered Output
This is the first line.
And this is the second line.
<p>This is the first line.<br>
And this is the second line.</p>

This is the first line.
And this is the second line.

Line Break Best Practices

You can use two or more spaces (commonly referred to as “trailing whitespace”) for line breaks in nearly every Markdown application, but it’s controversial. It’s hard to see trailing whitespace in an editor, and many people accidentally or intentionally put two spaces after every sentence. For this reason, you may want to use something other than trailing whitespace for line breaks. Fortunately, there is another option supported by nearly every Markdown application: the <br> HTML tag.

For compatibility, use trailing white space or the <br> HTML tag at the end of the line.

There are two other options I don’t recommend using. CommonMark and a few other lightweight markup languages let you type a backslash () at the end of the line, but not all Markdown applications support this, so it isn’t a great option from a compatibility perspective. And at least a couple lightweight markup languages don’t require anything at the end of the line — just type return and they’ll create a line break.

✅ Do this❌ Don't do this
First line with two spaces after.
And the next line.
First line with the HTML tag after.<br>
And the next line.
First line with a backslash after.
And the next line.
First line with nothing after.
And the next line.

Emphasis

You can add emphasis by making text bold or italic.

Bold

To bold text, add two asterisks or underscores before and after a word or phrase. To bold the middle of a word for emphasis, add two asterisks without spaces around the letters.

MarkdownHTMLRendered Output
I just love **bold text**.I just love <strong>bold text</strong>.I just love bold text.
I just love __bold text__.I just love <strong>bold text</strong>.I just love bold text.
Love**is**boldLove<strong>is</strong>boldLoveisbold
Gfm Markdown

Bold Best Practices

Markdown applications don’t agree on how to handle underscores in the middle of a word. For compatibility, use asterisks to bold the middle of a word for emphasis.

✅ Do this❌ Don't do this
Love**is**bold Love__is__bold

Italic

To italicize text, add one asterisk or underscore before and after a word or phrase. To italicize the middle of a word for emphasis, add one asterisk without spaces around the letters.

MarkdownHTMLRendered Output
Italicized text is the *cat's meow*.Italicized text is the <em>cat's meow</em>.Italicized text is the cat’s meow.
Italicized text is the _cat's meow_.Italicized text is the <em>cat's meow</em>.Italicized text is the cat’s meow.
A*cat*meowA<em>cat</em>meowAcatmeow

Italic Best Practices

Markdown applications don’t agree on how to handle underscores in the middle of a word. For compatibility, use asterisks to italicize the middle of a word for emphasis.

✅ Do this❌ Don't do this
A*cat*meow A_cat_meow

Bold and Italic

To emphasize text with bold and italics at the same time, add three asterisks or underscores before and after a word or phrase. To bold and italicize the middle of a word for emphasis, add three asterisks without spaces around the letters.

MarkdownHTMLRendered Output
This text is ***really important***.This text is <strong><em>really important</em></strong>.This text is really important.
This text is ___really important___.This text is <strong><em>really important</em></strong>.This text is really important.
This text is __*really important*__.This text is <strong><em>really important</em></strong>.This text is really important.
This text is **_really important_**.This text is <strong><em>really important</em></strong>.This text is really important.
This is really***very***important text.This is really<strong><em>very</em></strong>important text.This is reallyveryimportant text.

Bold and Italic Best Practices

Markdown applications don’t agree on how to handle underscores in the middle of a word. For compatibility, use asterisks to bold and italicize the middle of a word for emphasis.

✅ Do this❌ Don't do this
This is really***very***important text. This is really___very___important text.

Blockquotes

To create a blockquote, add a > in front of a paragraph.

The rendered output looks like this:

Dorothy followed her through many of the beautiful rooms in her castle.

Blockquotes with Multiple Paragraphs

Blockquotes can contain multiple paragraphs. Add a > on the blank lines between the paragraphs.

The rendered output looks like this:

Dorothy followed her through many of the beautiful rooms in her castle.

The Witch bade her clean the pots and kettles and sweep the floor and keep the fire fed with wood.

Nested Blockquotes

Blockquotes can be nested. Add a >> in front of the paragraph you want to nest.

The rendered output looks like this:

Dorothy followed her through many of the beautiful rooms in her castle.

The Witch bade her clean the pots and kettles and sweep the floor and keep the fire fed with wood.

Blockquotes with Other Elements

Blockquotes can contain other Markdown formatted elements. Not all elements can be used — you’ll need to experiment to see which ones work.

The rendered output looks like this:

Gfm Markdown File

The quarterly results look great!

  • Revenue was off the chart.
  • Profits were higher than ever.

Everything is going according to plan.

Lists

You can organize items into ordered and unordered lists.

Ordered Lists

To create an ordered list, add line items with numbers followed by periods. The numbers don’t have to be in numerical order, but the list should start with the number one.

MarkdownHTMLRendered Output
1. First item
2. Second item
3. Third item
4. Fourth item
<ol>
<li>First item</li>
<li>Second item</li>
<li>Third item</li>
<li>Fourth item</li>
</ol>
  1. First item
  2. Second item
  3. Third item
  4. Fourth item
1. First item
1. Second item
1. Third item
1. Fourth item
<ol>
<li>First item</li>
<li>Second item</li>
<li>Third item</li>
<li>Fourth item</li>
</ol>
  1. First item
  2. Second item
  3. Third item
  4. Fourth item
1. First item
8. Second item
3. Third item
5. Fourth item
<ol>
<li>First item</li>
<li>Second item</li>
<li>Third item</li>
<li>Fourth item</li>
</ol>
  1. First item
  2. Second item
  3. Third item
  4. Fourth item
1. First item
2. Second item
3. Third item
1. Indented item
2. Indented item
4. Fourth item
<ol>
<li>First item</li>
<li>Second item</li>
<li>Third item
<ol>
<li>Indented item</li>
<li>Indented item</li>
</ol>
</li>
<li>Fourth item</li>
</ol>
  1. First item
  2. Second item
  3. Third item
    1. Indented item
    2. Indented item
  4. Fourth item

Ordered List Best Practices

CommonMark and a few other lightweight markup languages let you use a parenthesis ()) as a delimiter (e.g., 1) First item), but not all Markdown applications support this, so it isn’t a great option from a compatibility perspective. For compatibility, use periods only.

✅ Do this❌ Don't do this
1. First item
2. Second item
1) First item
2) Second item

Unordered Lists

To create an unordered list, add dashes (-), asterisks (*), or plus signs (+) in front of line items. Indent one or more items to create a nested list.

MarkdownHTMLRendered Output
- First item
- Second item
- Third item
- Fourth item
<ul>
<li>First item</li>
<li>Second item</li>
<li>Third item</li>
<li>Fourth item</li>
</ul>
  • First item
  • Second item
  • Third item
  • Fourth item
* First item
* Second item
* Third item
* Fourth item
<ul>
<li>First item</li>
<li>Second item</li>
<li>Third item</li>
<li>Fourth item</li>
</ul>
  • First item
  • Second item
  • Third item
  • Fourth item
+ First item
+ Second item
+ Third item
+ Fourth item
<ul>
<li>First item</li>
<li>Second item</li>
<li>Third item</li>
<li>Fourth item</li>
</ul>
  • First item
  • Second item
  • Third item
  • Fourth item
- First item
- Second item
- Third item
- Indented item
- Indented item
- Fourth item
<ul>
<li>First item</li>
<li>Second item</li>
<li>Third item
<ul>
<li>Indented item</li>
<li>Indented item</li>
</ul>
</li>
<li>Fourth item</li>
</ul>
  • First item
  • Second item
  • Third item
    • Indented item
    • Indented item
  • Fourth item

Starting Unordered List Items With Numbers

If you need to start an unordered list item with a number followed by a period, you can use a backslash () to escape the period.

MarkdownHTMLRendered Output
- 1968. A great year!
- I think 1969 was second best.
<ul>
<li>1968. A great year!</li>
<li>I think 1969 was second best.</li>
</ul>
  • 1968. A great year!
  • I think 1969 was second best.

Unordered List Best Practices

Markdown applications don’t agree on how to handle different delimiters in the same list. For compatibility, don’t mix and match delimiters in the same list — pick one and stick with it.

✅ Do this❌ Don't do this
- First item
- Second item
- Third item
- Fourth item
+ First item
* Second item
- Third item
+ Fourth item

Adding Elements in Lists

To add another element in a list while preserving the continuity of the list, indent the element four spaces or one tab, as shown in the following examples.

Paragraphs

The rendered output looks like this:

  • This is the first list item.
  • Here’s the second list item.

    I need to add another paragraph below the second list item.

  • And here’s the third list item.

Blockquotes

The rendered output looks like this:

  • This is the first list item.
  • Here’s the second list item.

    A blockquote would look great below the second list item.

  • And here’s the third list item.

Code Blocks

Code blocks are normally indented four spaces or one tab. When they’re in a list, indent them eight spaces or two tabs.

The rendered output looks like this:

  1. Open the file.
  2. Find the following code block on line 21:

  3. Update the title to match the name of your website.

Gfm Markdown Preview

Images

The rendered output looks like this:

  1. Open the file containing the Linux mascot.
  2. Marvel at its beauty.

  3. Close the file.

Lists

You can nest an unordered list in an ordered list, or vice versa.

The rendered output looks like this:

  1. First item
  2. Second item
  3. Third item
    • Indented item
    • Indented item
  4. Fourth item

Code

To denote a word or phrase as code, enclose it in backticks (`).

MarkdownHTMLRendered Output
At the command prompt, type `nano`.At the command prompt, type <code>nano</code>. At the command prompt, type nano.

Escaping Backticks

If the word or phrase you want to denote as code includes one or more backticks, you can escape it by enclosing the word or phrase in double backticks (``).

MarkdownHTMLRendered Output
``Use `code` in your Markdown file.``<code>Use `code` in your Markdown file.</code>Use `code` in your Markdown file.

Code Blocks

To create code blocks, indent every line of the block by at least four spaces or one tab.

The rendered output looks like this:

Note: To create code blocks without indenting lines, use fenced code blocks.

Horizontal Rules

To create a horizontal rule, use three or more asterisks (***), dashes (---), or underscores (___) on a line by themselves.

Gfm Markdown

The rendered output of all three looks identical:

Horizontal Rule Best Practices

For compatibility, put blank lines before and after horizontal rules.

✅ Do this❌ Don't do this
Try to put a blank line before...
---
...and after a horizontal rule.
Without blank lines, this would be a heading.
---
Don't do this!

Links

To create a link, enclose the link text in brackets (e.g., [Duck Duck Go]) and then follow it immediately with the URL in parentheses (e.g., (https://duckduckgo.com)).

The rendered output looks like this:

My favorite search engine is Duck Duck Go.

Adding Titles

You can optionally add a title for a link. This will appear as a tooltip when the user hovers over the link. To add a title, enclose it in parentheses after the URL.

The rendered output looks like this:

My favorite search engine is Duck Duck Go.

URLs and Email Addresses

To quickly turn a URL or email address into a link, enclose it in angle brackets.

The rendered output looks like this:

https://www.markdownguide.org
fake@example.com

Formatting Links

To emphasize links, add asterisks before and after the brackets and parentheses. To denote links as code, add backticks in the brackets.

The rendered output looks like this:

I love supporting the EFF.
This is the Markdown Guide.
See the section on code.

Reference-style Links

Reference-style links are a special kind of link that make URLs easier to display and read in Markdown. Reference-style links are constructed in two parts: the part you keep inline with your text and the part you store somewhere else in the file to keep the text easy to read.

Formatting the First Part of the Link

The first part of a reference-style link is formatted with two sets of brackets. The first set of brackets surrounds the text that should appear linked. The second set of brackets displays a label used to point to the link you’re storing elsewhere in your document.

Although not required, you can include a space between the first and second set of brackets. The label in the second set of brackets is not case sensitive and can include letters, numbers, spaces, or punctuation.

This means the following example formats are roughly equivalent for the first part of the link:

  • [hobbit-hole][1]
  • [hobbit-hole] [1]

Formatting the Second Part of the Link

The second part of a reference-style link is formatted with the following attributes:

  1. The label, in brackets, followed immediately by a colon and at least one space (e.g., [label]: ).
  2. The URL for the link, which you can optionally enclose in angle brackets.
  3. The optional title for the link, which you can enclose in double quotes, single quotes, or parentheses.

This means the following example formats are all roughly equivalent for the second part of the link:

  • [1]: https://en.wikipedia.org/wiki/Hobbit#Lifestyle
  • [1]: https://en.wikipedia.org/wiki/Hobbit#Lifestyle 'Hobbit lifestyles'
  • [1]: https://en.wikipedia.org/wiki/Hobbit#Lifestyle 'Hobbit lifestyles'
  • [1]: https://en.wikipedia.org/wiki/Hobbit#Lifestyle (Hobbit lifestyles)
  • [1]: <https://en.wikipedia.org/wiki/Hobbit#Lifestyle> 'Hobbit lifestyles'
  • [1]: <https://en.wikipedia.org/wiki/Hobbit#Lifestyle> 'Hobbit lifestyles'
  • [1]: <https://en.wikipedia.org/wiki/Hobbit#Lifestyle> (Hobbit lifestyles)

You can place this second part of the link anywhere in your Markdown document. Some people place them immediately after the paragraph in which they appear while other people place them at the end of the document (like endnotes or footnotes).

An Example Putting the Parts Together

Say you add a URL as a standard URL link to a paragraph and it looks like this in Markdown:

Though it may point to interesting additional information, the URL as displayed really doesn’t add much to the existing raw text other than making it harder to read. To fix that, you could format the URL like this instead:

In both instances above, the rendered output would be identical:

In a hole in the ground there lived a hobbit. Not a nasty, dirty, wet hole, filled with the ends of worms and an oozy smell, nor yet a dry, bare, sandy hole with nothing in it to sit down on or to eat: it was a hobbit-hole, and that means comfort.

and the HTML for the link would be:

Link Best Practices

Markdown applications don’t agree on how to handle spaces in the middle of a URL. For compatibility, try to URL encode any spaces with %20.

✅ Do this❌ Don't do this
[link](https://www.example.com/my%20great%20page) [link](https://www.example.com/my great page)

Images

To add an image, add an exclamation mark (!), followed by alt text in brackets, and the path or URL to the image asset in parentheses. You can optionally add a title after the URL in the parentheses.

The rendered output looks like this:

Linking Images

To add a link to an image, enclose the Markdown for the image in brackets, and then add the link in parentheses.

The rendered output looks like this:

Escaping Characters

To display a literal character that would otherwise be used to format text in a Markdown document, add a backslash () in front of the character.

The rendered output looks like this:

* Without the backslash, this would be a bullet in an unordered list.

Characters You Can Escape

You can use a backslash to escape the following characters.

CharacterName
backslash
`backtick (see also escaping backticks in code)
*asterisk
_underscore
{ }curly braces
[ ]brackets
< >angle brackets
( )parentheses
#pound sign
+plus sign
-minus sign (hyphen)
.dot
!exclamation mark
|pipe (see also escaping pipe in tables)

HTML

Many Markdown applications allow you to use HTML tags in Markdown-formatted text. This is helpful if you prefer certain HTML tags to Markdown syntax. For example, some people find it easier to use HTML tags for images. Using HTML is also helpful when you need to change the attributes of an element, like specifying the color of text or changing the width of an image.

To use HTML, place the tags in the text of your Markdown-formatted file.

The rendered output looks like this:

This word is bold. This word is italic.

HTML Best Practices

For security reasons, not all Markdown applications support HTML in Markdown documents. When in doubt, check your Markdown application’s documentation. Some applications support only a subset of HTML tags.

Use blank lines to separate block-level HTML elements like <div>, <table>, <pre>, and <p> from the surrounding content. Try not to indent the tags with tabs or spaces — that can interfere with the formatting.

You can’t use Markdown syntax inside block-level HTML tags. For example, <p>italic and **bold**</p> won’t work.

Take your Markdown skills to the next level.

Learn Markdown in 60 pages. Designed for both novices and experts, The Markdown Guide book is a comprehensive reference that has everything you need to get started and master Markdown syntax.

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The marked function

ArgumentTypeNotes
markdownStringstringString of markdown source to be compiled.
optionsobjectHash of options. Can also use marked.setOptions.
callbackfunctionCalled when markdownString has been parsed. Can be used as second argument if no options present.

Alternative using reference

Options

MemberTypeDefaultSinceNotes
baseUrlstringnull0.3.9A prefix url for any relative link.
breaksbooleanfalsev0.2.7If true, add <br> on a single line break (copies GitHub behavior on comments, but not on rendered markdown files). Requires gfm be true.
gfmbooleantruev0.2.1If true, use approved GitHub Flavored Markdown (GFM) specification.
headerIdsbooleantruev0.4.0If true, include an id attribute when emitting headings (h1, h2, h3, etc).
headerPrefixstring'v0.3.0A string to prefix the id attribute when emitting headings (h1, h2, h3, etc).
highlightfunctionnullv0.3.0A function to highlight code blocks, see Asynchronous highlighting.
langPrefixstring'language-'v0.3.0A string to prefix the className in a <code> block. Useful for syntax highlighting.
manglebooleantruev0.3.4If true, autolinked email address is escaped with HTML character references.
pedanticbooleanfalsev0.2.1If true, conform to the original markdown.pl as much as possible. Don't fix original markdown bugs or behavior. Turns off and overrides gfm.
rendererobjectnew Renderer()v0.3.0An object containing functions to render tokens to HTML. See extensibility for more details.
sanitizebooleanfalsev0.2.1If true, sanitize the HTML passed into markdownString with the sanitizer function.
Warning: This feature is deprecated and it should NOT be used as it cannot be considered secure.
Instead use a sanitize library, like DOMPurify (recommended), sanitize-html or insane on the output HTML!
sanitizerfunctionnullv0.3.4A function to sanitize the HTML passed into markdownString.
silentbooleanfalsev0.2.7If true, the parser does not throw any exception.
smartListsbooleanfalsev0.2.8If true, use smarter list behavior than those found in markdown.pl.
smartypantsbooleanfalsev0.2.9If true, use 'smart' typographic punctuation for things like quotes and dashes.
tokenizerobjectnew Tokenizer()v1.0.0An object containing functions to create tokens from markdown. See extensibility for more details.
walkTokensfunctionnullv1.1.0A function which is called for every token. See extensibility for more details.
xhtmlbooleanfalsev0.3.2If true, emit self-closing HTML tags for void elements (<br/>, <img/>, etc.) with a '/' as required by XHTML.

Inline Markdown

You can parse inline markdown by running markdown through marked.parseInline.

Asynchronous highlighting

Unlike highlight.js the pygmentize.js library uses asynchronous highlighting. This example demonstrates that marked is agnostic when it comes to the highlighter you use.

In both examples, code is a string representing the section of code to pass to the highlighter. In this example, lang is a string informing the highlighter what programming language to use for the code and callback is the function the asynchronous highlighter will call once complete.

Workers

To prevent ReDoS attacks you can run marked on a worker and terminate it when parsing takes longer than usual.

Marked can be run in a worker thread on a node server, or a web worker in a browser.

Node Worker Thread

Web Worker

NOTE: Web Workers send the payload from postMessage in an object with the payload in a .data property