Available Options - Showdown

!!! warning "" Starting from the version 1.6.0 and earlier, all the options are disabled by default in the cli tool.

backslashEscapesHTMLTags

Support escaping of HTML tags.

type: boolean
default value: false
introduced in: 1.7.2

=== "input"

```html
\<div>foo\</div>
```

=== "output (value is true)"

```html
<p>&lt;div&gt;foo&lt;/div&gt;</p>
```

completeHTMLDocument

Output a complete HTML document, including <html>, <head>, and <body> tags instead of an HTML fragment.

type: boolean
default value: false
introduced in: 1.8.5

customizedHeaderId

Set custom ID for a heading.

!!! warning "" This option can be overridden with the noHeaderId option.

type: boolean
default value: false
introduced in: 1.7.0

=== "code"

```html
## Sample heading {mycustomid}
```

=== "output"

```html
<h1 id="mycustomid">This is a heading</h1>
```

!!! hint "" For better readability and human-friendliness of the heading IDs, it is also recommended to set the ghCompatibleHeaderId option to true.

disableForced4SpacesIndentedSublists

Disable the rule of 4 spaces to indent sub-lists. If enabled, this option effectively reverts to the old behavior where you can indent sub-lists with 2 or 3 spaces.

type: boolean
default value: false
introduced in: 1.5.0

=== "input"

```
- one
  - two

...

- one
    - two
```

=== "output (value is false)"

```html
<ul>
<li>one</li>
<li>two</li>
</ul>
<p>...</p>
<ul>
<li>one
    <ul>
        <li>two</li>
    </ul>
</li>
</ul>
```

=== "output (value is true)"

```html
<ul>
<li>one
    <ul>
        <li>two</li>
    </ul>
</li>
</ul>
<p>...</p>
<ul>
<li>one
    <ul>
        <li>two</li>
    </ul>
</li>
</ul>
```

emoji

Enable emoji support. For more info on available emojis, see https://github.com/showdownjs/showdown/wiki/Emojis (since v.1.8.0)

type: boolean
default value: false
introduced in: 1.8.0

=== "input"

```
this is a :smile: emoji
```

=== "output (value is false)"

```html
<p>this is a :smile: emoji</p>
```

=== "output (value is true)"

```html
<p>this is a 😄 emoji</p>
```

!!! hint "Full list of supported emojies"

Check the [Showdown Wiki](https://github.com/showdownjs/showdown/wiki/Emojis#emoji-list) for a full list of supported emojies.

encodeEmails

Enable automatic obfuscation of email addresses. During this process, email addresses are encoded via Character Entities, transforming ASCII email addresses into their equivalent decimal entities.

type: boolean
default value: false
introduced in: 1.6.1

=== "input"

```
<[email protected]>
```

=== "output (value is false)"

```html
<a href="mailto:[email protected]">[email protected]</a>
```

=== "output (value is true)"

```html
<a href="&#109;&#97;&#105;&#108;t&#x6f;&#x3a;&#109;&#x79;s&#x65;&#x6c;&#102;&#64;&#x65;xa&#109;&#112;&#108;&#101;&#x2e;c&#x6f;&#109;">&#x6d;&#121;s&#101;&#108;f&#x40;&#x65;&#120;a&#x6d;&#x70;&#108;&#x65;&#x2e;&#99;&#x6f;&#109;</a>
```

excludeTrailingPunctuationFromURLs

Exclude trailing punctuation from autolinked URLs: . ! ? ( )

This option applies only to links generated by simplifiedAutoLink.

type: boolean
default value: false
introduced in: 1.5.1

=== "input"

```
   check this link www.google.com.
```

=== "output (value is false)"

```html
<p>check this link <a href="www.google.com">www.google.com.</a></p>
```

=== "output (value is true)"

```html
<p>check this link <a href="www.google.com">www.google.com</a>.</p>
```

ghCodeBlocks

Enable support for GFM code block style syntax (fenced codeblocks).

type: boolean
default value: true
introduced in: 0.3.1

=== "example"

```
 ```
 some code here
 ```
```

ghCompatibleHeaderId

Generate heading IDs compatible with GitHub style: spaces are replaced with dashes, and certain non-alphanumeric chars are removed.

!!! warning "" This option can be overridden with the noHeaderId option.

type: boolean
default value: false
introduced in: 1.5.5

=== "input"

```
# This is a heading with @#$%
```

=== "output (value is false)"

```html
<h1 id="thisisaheading">This is a heading</h1>
```

=== "output (value is true)"

```html
<h1 id="this-is-a-heading-with-">This is a heading with @#$%</h1>
```

ghMentions

Enables support for GitHub @mentions that allows you to link to the GitHub profile page of the mentioned username.

type: boolean
default value: false
introduced in: 1.6.0

=== "input"

```
hello there @tivie
```

=== "output (value is false)"

```html
<p>hello there @tivie</p>
```

=== "output (value is true)"

```html
<p>hello there <a href="https://www.github.com/tivie">@tivie</a></p>
```

ghMentionsLink

Specify where the link generated by @mentions should point to. Works only when ghMentions: true.

type: boolean
default value: https://github.com/{u}
introduced in: 1.6.2

=== "input"

```
hello there @tivie
```

=== "output (value is https://github.com/{u})"

```html
<p>hello there <a href="https://www.github.com/tivie">@tivie</a></p>
```

=== "output (value is http://mysite.com/{u}/profile)"

```html
<p>hello there <a href="//mysite.com/tivie/profile">@tivie</a></p>
```

headerLevelStart

Set starting level for the heading tags.

type: integer
default value: 1
introduced in: 1.1.0

=== "input"

```
# This is a heading
```

=== "output (value is 1)"

```html
<h1>This is a heading</h1>
```

=== "output (value is 3)"

```html
<h3>This is a heading</h3>
```

literalMidWordUnderscores

Treat underscores in the middle of words as literal characters.

Underscores allow you to specify the words that should be emphasized. However, in some cases, this may be unwanted behavior. With this option enabled, underscores in the middle of words will no longer be interpreted as <em> and <strong>, but as literal underscores.

type: boolean
default value: false
introduced in: 1.2.0

=== "input"

```
some text with__underscores__in the middle
```

=== "output (value is false)"

```html
<p>some text with<strong>underscores</strong>in the middle</p>
```

=== "output (value is true)"

```html
<p>some text with__underscores__in the middle</p>
```

metadata

Enable support for document metadata (front-matter). You can define metadata at the top of a document between ««« »»» or --- --- symbols.

type: boolean
default value: false
introduced in: 1.8.5

=== "input"

```js
let ref = `referenced value`;

var markdown = `
---
first: Lorem
second: Ipsum
ref_variable: ${ref}
---
`

var conv = new showdown.Converter({metadata: true});
var html = conv.makeHtml(markdown);
var metadata = conv.getMetadata();
```

=== "output (value is true)"

```js
// console.log(metadata)
{
    first: 'Lorem',
    second: 'Ipsum',
    ref_variable: 'referenced value'
}
```

noHeaderId

Disable automatic generation of heading IDs.

!!! warning "" Setting the option to true overrides the following options:

* [`prefixHeaderId`](#prefixheaderid)
* [`customizedHeaderId`](#customizedheaderid)
* [`ghCompatibleHeaderId`](#ghcompatibleheaderid)

type: boolean
default value: false
introduced in: 1.1.0

=== "input"

```
# This is a heading
```

=== "output (value is false)"

```html
<h1 id="thisisaheading">This is a heading</h1>
```

=== "output (value is true)"

```html
<h1>This is a heading</h1>
```

omitExtraWLInCodeBlocks

Omit trailing newline in code blocks (which is set by default before the closing tag). This option affects both indented and fenced (gfm style) code blocks.

type: boolean
default value: false
introduced in: 1.0.0

=== "input"

```
    var foo = 'bar';
```

=== "output (value is false)"

```html
<code><pre>var foo = 'bar';
</pre></code>
```

=== "output (value is true)"

```html
<code><pre>var foo = 'bar';</pre></code>
```

openLinksInNewWindow

Open links in new windows.

type: boolean
default value: false
introduced in: 1.7.0

=== "input"

```
[link](https://google.com)
```

=== "output (value is false)"

```html
<a href="https://google.com">link</a>
```

=== "output (value is true)"

```html
<a href="https://google.com" rel="noopener noreferrer" target="_blank">link</a>
```

parseImgDimensions

Set image dimensions from within Markdown syntax.

type: boolean
default value: false
introduced in: 1.1.0

=== "example"

```
![foo](foo.jpg =100x80)   set width to 100px and height to 80px
![bar](bar.jpg =100x*)    set width to 100px and height to "auto"
![baz](baz.jpg =80%x5em)  set width to 80% and height to 5em
```

prefixHeaderId

Add a prefix to the generated heading ID:

Passing a string will add that string to the heading ID.
Passing true will add a generic section prefix.

!!! warning "" This option can be overridden with the noHeaderId option.

type: string / boolean
default value: false

=== "input"

```
# This is a heading
```

=== "output (value is false)"

```html
<h1 id="thisisaheading">This is a heading</h1>
```

=== "output (value is true)"

```html
<h1 id="sectionthisisaheading">This is a heading</h1>
```

=== "output (value is showdown)"

 ```html
 <h1 id="showdownthisisaheading">This is a heading</h1>
 ```

rawHeaderId

Replace (space), ' (single quote), and " (double quote) with - (dash) in the generated heading IDs, including prefixes.

!!! danger "" Use with caution as it might result in malformed IDs.

type:
default value:
introduced in: 1.7.3

rawPrefixHeaderId

Prevent Showndown from modifying the prefix. Works only when prefixHeaderId is set to a string value.

!!! danger "" Use with caution as it might result in malformed IDs. For example, when the prefix contains special characters like " \ / or others.

type: boolean
default value: false
introduced in: 1.7.3

requireSpaceBeforeHeadingText

Require a space between a heading # and the heading text.

type: boolean
default value: false
introduced in: 1.5.3

=== "input"

```
#heading
```

=== "output (value is false)"

```html
<h1 id="heading">heading</h1>
```

=== "output (value is true)"

```html
<p>#heading</p>
```

simpleLineBreaks

Parse line breaks as in paragraphs (GitHub-style behavior).

type: boolean
default value: false
introduced in: 1.5.1

=== "input"

```
a line
wrapped in two
```

=== "output (value is false)"

```html
<p>a line
wrapped in two</p>
```

=== "output (value is true)"

```html
<p>a line

wrapped in two</p>
```

simplifiedAutoLink

Enable automatic linking for plain text URLs.

type: boolean
default value: false
introduced in: 1.2.0

=== "input"

```
Lorem ipsum www.google.com
```

=== "output (value is false)"

```html
<p>Lorem ipsum www.google.com</p>
```

=== "output (value is true)"

```html
<p>Lorem ipsum <a href="www.google.com">www.google.com</a></p>
```

smartIndentationFix

Resolve indentation problems related to ES6 template strings in the midst of indented code.

type: boolean
default value: false
introduced in: 1.4.2

smoothLivePreview

Resolve an awkward effect when a paragraph is followed by a list. This effect appears on some circumstances, in live preview editors.

type: boolean
default value: false
introduced in: 1.2.1

!!! example "awkward effect"

![](http://i.imgur.com/YQ9iHTL.gif)

splitAdjacentBlockquotes

Split adjacent blockquote blocks.

type: boolean
default value: false
introduced in: 1.8.6

=== "input"

```
> Quote #1
>> Sub-quote 1

> Quote #2
>> Sub-quote 2
```

=== "output (value is false)"

```html
<blockquote>
  <p>Quote #1</p>
  <blockquote>
    <p>Sub-quote 1</p>
  </blockquote>
  <p>Quote #2</p>
  <blockquote>
    <p>Sub-quote 2</p>
  </blockquote>
</blockquote>
```

=== "output (value is true)"

```html
<blockquote>
  <p>Quote #1</p>
  <blockquote>
    <p>Sub-quote 1</p>
  </blockquote>
</blockquote>
<blockquote>
  <p>Quote #2</p>
  <blockquote>
    <p>Sub-quote 2</p>
  </blockquote>
</blockquote>    
```

strikethrough

Enable support for strikethrough (<del>).

type: boolean
default value: false
introduced in: 1.2.0

=== "input"

```
~~strikethrough~~
```

=== "output (value is true)"

```html
<del>strikethrough</del>
```

tables

Enable support for tables syntax.

type: boolean
default value: false
introduced in: 1.2.0

=== "example"

```
| h1    |    h2   |      h3 |
|:------|:-------:|--------:|
| 100   | [a][1]  | ![b][2] |
| *foo* | **bar** | ~~baz~~ |
```

tablesHeaderId

Generate automatic IDs for table headings. Works only when tables: true.

type: boolean
default value: false
introduced in: 1.2.0

tasklists

Enable support for GitHub style tasklists.

type: boolean
default value: false
introduced in: 1.2.0

=== "example"

```
 - [x] This task is done
 - [ ] This task is still pending
```

underline

Enable support for underline. If enabled, underscores will no longer be parsed as <em> and <strong>.

type: boolean
default value: false
status: Experimental

=== "example"

```
__underlined word__     // double underscores

___underlined word___   // triple underscores
```