Full markdown syntax taken from John Gruber’s Daring Fireball.Did you know that 9 out of 10 bloggers prefer to write in markdown?
Markdown: Syntax
Note: This document is itself written using Markdown; youcan see the source for it by adding ‘.text’ to the URL.
Overview
Philosophy
Markdown is intended to be as easy-to-read and easy-to-write as is feasible.
Readability, however, is emphasized above all else. A Markdown-formatteddocument should be publishable as-is, as plain text, without lookinglike it’s been marked up with tags or formatting instructions. WhileMarkdown’s syntax has been influenced by several existing text-to-HTMLfilters – including Setext, atx, Textile, reStructuredText,Grutatext, and EtText – the single biggest source ofinspiration for Markdown’s syntax is the format of plain text email.
To this end, Markdown’s syntax is comprised entirely of punctuationcharacters, which punctuation characters have been carefully chosen soas to look like what they mean. E.g., asterisks around a word actuallylook like *emphasis*. Markdown lists look like, well, lists. Evenblockquotes look like quoted passages of text, assuming you’ve everused email.
Inline HTML
Markdown’s syntax is intended for one purpose: to be used as aformat for writing for the web.
Markdown is not a replacement for HTML, or even close to it. Itssyntax is very small, corresponding only to a very small subset ofHTML tags. The idea is not to create a syntax that makes it easierto insert HTML tags. In my opinion, HTML tags are already easy toinsert. The idea for Markdown is to make it easy to read, write, andedit prose. HTML is a publishing format; Markdown is a writingformat. Thus, Markdown’s formatting syntax only addresses issues thatcan be conveyed in plain text.
For any markup that is not covered by Markdown’s syntax, you simplyuse HTML itself. There’s no need to preface it or delimit it toindicate that you’re switching from Markdown to HTML; you just usethe tags.
The only restrictions are that block-level HTML elements – e.g. <div>,<table>, <pre>, <p>, etc. – must be separated from surroundingcontent by blank lines, and the start and end tags of the block shouldnot be indented with tabs or spaces. Markdown is smart enough notto add extra (unwanted) <p> tags around HTML block-level tags.
For example, to add an HTML table to a Markdown article:
This is a regular paragraph.
<table>
<tr>
<td>Foo</td>
</tr>
</table>
This is another regular paragraph.
Note that Markdown formatting syntax is not processed within block-levelHTML tags. E.g., you can’t use Markdown-style *emphasis* inside anHTML block.
Span-level HTML tags – e.g. <span>, <cite>, or <del> – can beused anywhere in a Markdown paragraph, list item, or header. If youwant, you can even use HTML tags instead of Markdown formatting; e.g. ifyou’d prefer to use HTML <a> or <img> tags instead of Markdown’slink or image syntax, go right ahead.
Unlike block-level HTML tags, Markdown syntax is processed withinspan-level tags.
Automatic Escaping for Special Characters
In HTML, there are two characters that demand special treatment: <and &. Left angle brackets are used to start tags; ampersands areused to denote HTML entities. If you want to use them as literalcharacters, you must escape them as entities, e.g. <, and&.
Ampersands in particular are bedeviling for web writers. If you want towrite about ‘AT&T’, you need to write ‘AT&T‘. You even need toescape ampersands within URLs. Thus, if you want to link to:
http://images.google.com/images?num=30&q=larry+bird
you need to encode the URL as:
http://images.google.com/images?num=30&q=larry+bird
in your anchor tag href attribute. Needless to say, this is easy toforget, and is probably the single most common source of HTML validationerrors in otherwise well-marked-up web sites.
Markdown allows you to use these characters naturally, taking care ofall the necessary escaping for you. If you use an ampersand as part ofan HTML entity, it remains unchanged; otherwise it will be translatedinto &.
So, if you want to include a copyright symbol in your article, you can write:
©
and Markdown will leave it alone. But if you write:
AT&T
Markdown will translate it to:
AT&T
Similarly, because Markdown supports inline HTML, if you useangle brackets as delimiters for HTML tags, Markdown will treat them assuch. But if you write:
4 < 5
Markdown will translate it to:
4 < 5
However, inside Markdown code spans and blocks, angle brackets andampersands are always encoded automatically. This makes it easy to useMarkdown to write about HTML code. (As opposed to raw HTML, which is aterrible format for writing about HTML syntax, because every single <and & in your example code needs to be escaped.)
Block Elements
Paragraphs and Line Breaks
A paragraph is simply one or more consecutive lines of text, separatedby one or more blank lines. (A blank line is any line that looks like ablank line – a line containing nothing but spaces or tabs is consideredblank.) Normal paragraphs should not be indented with spaces or tabs.
The implication of the “one or more consecutive lines of text” rule isthat Markdown supports “hard-wrapped” text paragraphs. This differssignificantly from most other text-to-HTML formatters (including MovableType’s “Convert Line Breaks” option) which translate every line breakcharacter in a paragraph into a <br /> tag.
When you do want to insert a <br /> break tag using Markdown, youend a line with two or more spaces, then type return.
Yes, this takes a tad more effort to create a <br />, but a simplistic“every line break is a <br />“ rule wouldn’t work for Markdown.Markdown’s email-style blockquoting and multi-paragraph list itemswork best – and look better – when you format them with hard breaks.
Headers
Markdown supports two styles of headers, Setext and atx.
Setext-style headers are “underlined” using equal signs (for first-levelheaders) and dashes (for second-level headers). For example:
This is an H1
=============
This is an H2
-------------
Any number of underlining =‘s or -‘s will work.
Atx-style headers use 1-6 hash characters at the start of the line,corresponding to header levels 1-6. For example:
# This is an H1
## This is an H2
###### This is an H6
Optionally, you may “close” atx-style headers. This is purelycosmetic – you can use this if you think it looks better. Theclosing hashes don’t even need to match the number of hashesused to open the header. (The number of opening hashesdetermines the header level.) :
# This is an H1 #
## This is an H2 ##
### This is an H3 ######
Blockquotes
Markdown uses email-style > characters for blockquoting. If you’refamiliar with quoting passages of text in an email message, then youknow how to create a blockquote in Markdown. It looks best if you hardwrap the text and put a > before every line:
> This is a blockquote with two paragraphs. Lorem ipsum dolor sit amet,
> consectetuer adipiscing elit. Aliquam hendrerit mi posuere lectus.
> Vestibulum enim wisi, viverra nec, fringilla in, laoreet vitae, risus.
>
> Donec sit amet nisl. Aliquam semper ipsum sit amet velit. Suspendisse
> id sem consectetuer libero luctus adipiscing.
Markdown allows you to be lazy and only put the > before the firstline of a hard-wrapped paragraph:
> This is a blockquote with two paragraphs. Lorem ipsum dolor sit amet,
consectetuer adipiscing elit. Aliquam hendrerit mi posuere lectus.
Vestibulum enim wisi, viverra nec, fringilla in, laoreet vitae, risus.
> Donec sit amet nisl. Aliquam semper ipsum sit amet velit. Suspendisse
id sem consectetuer libero luctus adipiscing.
Blockquotes can be nested (i.e. a blockquote-in-a-blockquote) byadding additional levels of >:
> This is the first level of quoting.
>
> > This is nested blockquote.
>
> Back to the first level.
Blockquotes can contain other Markdown elements, including headers, lists,and code blocks:
This is a header.
- This is the first list item.
- This is the second list item.
Here’s some example code:
return shell_exec("echo $input | $markdown_script");
Any decent text editor should make email-style quoting easy. Forexample, with BBEdit, you can make a selection and choose IncreaseQuote Level from the Text menu.
Lists
Markdown supports ordered (numbered) and unordered (bulleted) lists.
Unordered lists use asterisks, pluses, and hyphens – interchangably– as list markers:
* Red
* Green
* Blue
is equivalent to:
+ Red
+ Green
+ Blue
and:
- Red
- Green
- Blue
Ordered lists use numbers followed by periods:
1. Bird
2. McHale
3. Parish
It’s important to note that the actual numbers you use to mark thelist have no effect on the HTML output Markdown produces. The HTMLMarkdown produces from the above list is:
<ol>
<li>Bird</li>
<li>McHale</li>
<li>Parish</li>
</ol>
If you instead wrote the list in Markdown like this:
1. Bird
1. McHale
1. Parish
or even:
3. Bird
1. McHale
8. Parish
you’d get the exact same HTML output. The point is, if you want to,you can use ordinal numbers in your ordered Markdown lists, so thatthe numbers in your source match the numbers in your published HTML.But if you want to be lazy, you don’t have to.
If you do use lazy list numbering, however, you should still start thelist with the number 1. At some point in the future, Markdown may supportstarting ordered lists at an arbitrary number.
List markers typically start at the left margin, but may be indented byup to three spaces. List markers must be followed by one or more spacesor a tab.
To make lists look nice, you can wrap items with hanging indents:
* Lorem ipsum dolor sit amet, consectetuer adipiscing elit.
Aliquam hendrerit mi posuere lectus. Vestibulum enim wisi,
viverra nec, fringilla in, laoreet vitae, risus.
* Donec sit amet nisl. Aliquam semper ipsum sit amet velit.
Suspendisse id sem consectetuer libero luctus adipiscing.
But if you want to be lazy, you don’t have to:
* Lorem ipsum dolor sit amet, consectetuer adipiscing elit.
Aliquam hendrerit mi posuere lectus. Vestibulum enim wisi,
viverra nec, fringilla in, laoreet vitae, risus.
* Donec sit amet nisl. Aliquam semper ipsum sit amet velit.
Suspendisse id sem consectetuer libero luctus adipiscing.
If list items are separated by blank lines, Markdown will wrap theitems in <p> tags in the HTML output. For example, this input:
* Bird
* Magic
will turn into:
<ul>
<li>Bird</li>
<li>Magic</li>
</ul>
But this:
* Bird
* Magic
will turn into:
<ul>
<li><p>Bird</p></li>
<li><p>Magic</p></li>
</ul>
List items may consist of multiple paragraphs. Each subsequentparagraph in a list item must be indented by either 4 spacesor one tab:
1. This is a list item with two paragraphs. Lorem ipsum dolor
sit amet, consectetuer adipiscing elit. Aliquam hendrerit
mi posuere lectus.
Vestibulum enim wisi, viverra nec, fringilla in, laoreet
vitae, risus. Donec sit amet nisl. Aliquam semper ipsum
sit amet velit.
2. Suspendisse id sem consectetuer libero luctus adipiscing.
It looks nice if you indent every line of the subsequentparagraphs, but here again, Markdown will allow you to belazy:
* This is a list item with two paragraphs.
This is the second paragraph in the list item. You're
only required to indent the first line. Lorem ipsum dolor
sit amet, consectetuer adipiscing elit.
* Another item in the same list.
To put a blockquote within a list item, the blockquote’s >delimiters need to be indented:
* A list item with a blockquote:
> This is a blockquote
> inside a list item.
To put a code block within a list item, the code block needsto be indented twice – 8 spaces or two tabs:
* A list item with a code block:
<code goes here>
It’s worth noting that it’s possible to trigger an ordered list byaccident, by writing something like this:
1986. What a great season.
In other words, a number-period-space sequence at the beginning of aline. To avoid this, you can backslash-escape the period:
1986\. What a great season.
Code Blocks
Pre-formatted code blocks are used for writing about programming ormarkup source code. Rather than forming normal paragraphs, the linesof a code block are interpreted literally. Markdown wraps a code blockin both <pre> and <code> tags.
To produce a code block in Markdown, simply indent every line of theblock by at least 4 spaces or 1 tab. For example, given this input:
This is a normal paragraph:
This is a code block.
Markdown will generate:
<p>This is a normal paragraph:</p>
<pre><code>This is a code block.
</code></pre>
One level of indentation – 4 spaces or 1 tab – is removed from eachline of the code block. For example, this:
Here is an example of AppleScript:
tell application "Foo"
beep
end tell
will turn into:
<p>Here is an example of AppleScript:</p>
<pre><code>tell application "Foo"
beep
end tell
</code></pre>
A code block continues until it reaches a line that is not indented(or the end of the article).
Within a code block, ampersands (&) and angle brackets (< and >)are automatically converted into HTML entities. This makes it veryeasy to include example HTML source code using Markdown – just pasteit and indent it, and Markdown will handle the hassle of encoding theampersands and angle brackets. For example, this:
<div class="footer">
© 2004 Foo Corporation
</div>
will turn into:
<pre><code><div class="footer">
&copy; 2004 Foo Corporation
</div>
</code></pre>
Regular Markdown syntax is not processed within code blocks. E.g.,asterisks are just literal asterisks within a code block. This meansit’s also easy to use Markdown to write about Markdown’s own syntax.
Horizontal Rules
You can produce a horizontal rule tag (<hr />) by placing three ormore hyphens, asterisks, or underscores on a line by themselves. If youwish, you may use spaces between the hyphens or asterisks. Each of thefollowing lines will produce a horizontal rule:
* * *
***
*****
- - -
---------------------------------------
Span Elements
Links
Markdown supports two style of links: inline and reference.
In both styles, the link text is delimited by [square brackets].
To create an inline link, use a set of regular parentheses immediatelyafter the link text’s closing square bracket. Inside the parentheses,put the URL where you want the link to point, along with an optionaltitle for the link, surrounded in quotes. For example:
This is [an example](http://example.com/ "Title") inline link.
[This link](http://example.net/) has no title attribute.
Will produce:
<p>This is <a href="http://example.com/" title="Title">
an example</a> inline link.</p>
<p><a href="http://example.net/">This link</a> has no
title attribute.</p>
If you’re referring to a local resource on the same server, you canuse relative paths:
See my [About](/about/) page for details.
Reference-style links use a second set of square brackets, insidewhich you place a label of your choosing to identify the link:
This is [an example][id] reference-style link.
You can optionally use a space to separate the sets of brackets:
This is [an example] [id] reference-style link.
Then, anywhere in the document, you define your link label like this,on a line by itself:
[id]: http://example.com/ "Optional Title Here"
That is:
- Square brackets containing the link identifier (optionallyindented from the left margin using up to three spaces);
- followed by a colon;
- followed by one or more spaces (or tabs);
- followed by the URL for the link;
- optionally followed by a title attribute for the link, enclosedin double or single quotes, or enclosed in parentheses.
The following three link definitions are equivalent:
foo: http://example.com/ ‘Optional Title Here’
Note: There is a known bug in Markdown.pl 1.0.1 which preventssingle quotes from being used to delimit link titles.
The link URL may, optionally, be surrounded by angle brackets:
[id]: <http://example.com/> "Optional Title Here"
You can put the title attribute on the next line and use extra spacesor tabs for padding, which tends to look better with longer URLs:
[id]: http://example.com/longish/path/to/resource/here
"Optional Title Here"
Link definitions are only used for creating links during Markdownprocessing, and are stripped from your document in the HTML output.
Link definition names may consist of letters, numbers, spaces, andpunctuation – but they are not case sensitive. E.g. these twolinks:
[link text][a][link text][A]
are equivalent.
The implicit link name shortcut allows you to omit the name of thelink, in which case the link text itself is used as the name.Just use an empty set of square brackets – e.g., to link the word“Google” to the google.com web site, you could simply write:
And then define the link:
Because link names may contain spaces, this shortcut even works formultiple words in the link text:
Visit Daring Fireball for more information.
And then define the link:
Link definitions can be placed anywhere in your Markdown document. Itend to put them immediately after each paragraph in which they’reused, but if you want, you can put them all at the end of yourdocument, sort of like footnotes.
Here’s an example of reference links in action:
I get 10 times more traffic from [Google] [1] than from
[Yahoo] [2] or [MSN] [3].
[1]: http://google.com/ "Google"
[2]: http://search.yahoo.com/ "Yahoo Search"
[3]: http://search.msn.com/ "MSN Search"
Using the implicit link name shortcut, you could instead write:
I get 10 times more traffic from [Google][] than from
[Yahoo][] or [MSN][].
[google]: http://google.com/ "Google"
[yahoo]: http://search.yahoo.com/ "Yahoo Search"
[msn]: http://search.msn.com/ "MSN Search"
Both of the above examples will produce the following HTML output:
<p>I get 10 times more traffic from <a href="http://google.com/"
title="Google">Google</a> than from
<a href="http://search.yahoo.com/" title="Yahoo Search">Yahoo</a>
or <a href="http://search.msn.com/" title="MSN Search">MSN</a>.</p>
For comparison, here is the same paragraph written usingMarkdown’s inline link style:
I get 10 times more traffic from [Google](http://google.com/ "Google")
than from [Yahoo](http://search.yahoo.com/ "Yahoo Search") or
[MSN](http://search.msn.com/ "MSN Search").
The point of reference-style links is not that they’re easier towrite. The point is that with reference-style links, your documentsource is vastly more readable. Compare the above examples: usingreference-style links, the paragraph itself is only 81 characterslong; with inline-style links, it’s 176 characters; and as raw HTML,it’s 234 characters. In the raw HTML, there’s more markup than thereis text.
With Markdown’s reference-style links, a source document much moreclosely resembles the final output, as rendered in a browser. Byallowing you to move the markup-related metadata out of the paragraph,you can add links without interrupting the narrative flow of yourprose.
Emphasis
Markdown treats asterisks (*) and underscores (_) as indicators ofemphasis. Text wrapped with one * or _ will be wrapped with anHTML <em> tag; double *‘s or _‘s will be wrapped with an HTML<strong> tag. E.g., this input:
*single asterisks*
_single underscores_
**double asterisks**
__double underscores__
will produce:
<em>single asterisks</em>
<em>single underscores</em>
<strong>double asterisks</strong>
<strong>double underscores</strong>
You can use whichever style you prefer; the lone restriction is thatthe same character must be used to open and close an emphasis span.
Emphasis can be used in the middle of a word:
un*frigging*believable
But if you surround an * or _ with spaces, it’ll be treated as aliteral asterisk or underscore.
To produce a literal asterisk or underscore at a position where itwould otherwise be used as an emphasis delimiter, you can backslashescape it:
\*this text is surrounded by literal asterisks\*
Code
To indicate a span of code, wrap it with backtick quotes (` ).Unlike a pre-formatted code block, a code span indicates code within anormal paragraph. For example:
Use the `printf()` function.
will produce:
<p>Use the <code>printf()</code> function.</p>
To include a literal backtick character within a code span, you can usemultiple backticks as the opening and closing delimiters:
``There is a literal backtick (`) here.``
which will produce this:
<p><code>There is a literal backtick (`) here.</code></p>
The backtick delimiters surrounding a code span may include spaces –one after the opening, one before the closing. This allows you to placeliteral backtick characters at the beginning or end of a code span:
A single backtick in a code span: `
A backtick-delimited string in a code span: `foo`
will produce:
A single backtick in a code span: `
A backtick-delimited string in a code span: foo
With a code span, ampersands and angle brackets are encoded as HTMLentities automatically, which makes it easy to include example HTMLtags. Markdown will turn this:
Please don't use any `<blink>` tags.
into:
<p>Please don't use any <code><blink></code> tags.</p>
You can write this:
`—` is the decimal-encoded equivalent of `—`.
to produce:
<p><code>&#8212;</code> is the decimal-encoded
equivalent of <code>&mdash;</code>.</p>
Images
Admittedly, it’s fairly difficult to devise a “natural” syntax forplacing images into a plain text document format.
Markdown uses an image syntax that is intended to resemble the syntaxfor links, allowing for two styles: inline and reference.
Inline image syntax looks like this:
That is:
- An exclamation mark:
!; - followed by a set of square brackets, containing the
altattribute text for the image; - followed by a set of parentheses, containing the URL or path tothe image, and an optional
titleattribute enclosed in doubleor single quotes.
Reference-style image syntax looks like this:
![Alt text][id]
Where “id” is the name of a defined image reference. Image referencesare defined using syntax identical to link references:
[id]: url/to/image "Optional title attribute"
As of this writing, Markdown has no syntax for specifying thedimensions of an image; if this is important to you, you can simplyuse regular HTML <img> tags.
Miscellaneous
Automatic Links
Markdown supports a shortcut style for creating “automatic” links for URLs and email addresses: simply surround the URL or email address with angle brackets. What this means is that if you want to show the actual text of a URL or email address, and also have it be a clickable link, you can do this:
<http://example.com/>
Markdown will turn this into:
<a href="http://example.com/">http://example.com/</a>
Automatic links for email addresses work similarly, except thatMarkdown will also perform a bit of randomized decimal and hexentity-encoding to help obscure your address from address-harvestingspambots. For example, Markdown will turn this:
<address@example.com>
into something like this:
<a href="mailto:addre
ss@example.co
m">address@exa
mple.com</a>
which will render in a browser as a clickable link to “address@example.com”.
(This sort of entity-encoding trick will indeed fool many, if notmost, address-harvesting bots, but it definitely won’t fool all ofthem. It’s better than nothing, but an address published in this waywill probably eventually start receiving spam.)
Backslash Escapes
Markdown allows you to use backslash escapes to generate literalcharacters which would otherwise have special meaning in Markdown’sformatting syntax. For example, if you wanted to surround a wordwith literal asterisks (instead of an HTML <em> tag), you can usebackslashes before the asterisks, like this:
\*literal asterisks\*
Markdown provides backslash escapes for the following characters:
\ backslash
` backtick
* asterisk
_ underscore
{} curly braces
[] square brackets
() parentheses
# hash mark
- plus sign
- minus sign (hyphen). dot! exclamation mark