4 <ul id="ProjectSubmenu">
5 <li><a href="/projects/markdown/" title="Markdown Project Page">Main</a></li>
6 <li><a href="/projects/markdown/basics" title="Markdown Basics">Basics</a></li>
7 <li><a class="selected" title="Markdown Syntax Documentation">Syntax</a></li>
8 <li><a href="/projects/markdown/license" title="Pricing and License Information">License</a></li>
9 <li><a href="/projects/markdown/dingus" title="Online Markdown Web Form">Dingus</a></li>
13 * [Overview](#overview)
14 * [Philosophy](#philosophy)
15 * [Inline HTML](#html)
16 * [Automatic Escaping for Special Characters](#autoescape)
17 * [Block Elements](#block)
18 * [Paragraphs and Line Breaks](#p)
20 * [Blockquotes](#blockquote)
22 * [Code Blocks](#precode)
23 * [Horizontal Rules](#hr)
24 * [Span Elements](#span)
29 * [Miscellaneous](#misc)
30 * [Backslash Escapes](#backslash)
31 * [Automatic Links](#autolink)
34 **Note:** This document is itself written using Markdown; you
35 can [see the source for it by adding '.text' to the URL][src].
37 [src]: /projects/markdown/syntax.text
41 <h2 id="overview">Overview</h2>
43 <h3 id="philosophy">Philosophy</h3>
45 Markdown is intended to be as easy-to-read and easy-to-write as is feasible.
47 Readability, however, is emphasized above all else. A Markdown-formatted
48 document should be publishable as-is, as plain text, without looking
49 like it's been marked up with tags or formatting instructions. While
50 Markdown's syntax has been influenced by several existing text-to-HTML
51 filters -- including [Setext] [1], [atx] [2], [Textile] [3], [reStructuredText] [4],
52 [Grutatext] [5], and [EtText] [6] -- the single biggest source of
53 inspiration for Markdown's syntax is the format of plain text email.
55 [1]: http://docutils.sourceforge.net/mirror/setext.html
56 [2]: http://www.aaronsw.com/2002/atx/
57 [3]: http://textism.com/tools/textile/
58 [4]: http://docutils.sourceforge.net/rst.html
59 [5]: http://www.triptico.com/software/grutatxt.html
60 [6]: http://ettext.taint.org/doc/
62 To this end, Markdown's syntax is comprised entirely of punctuation
63 characters, which punctuation characters have been carefully chosen so
64 as to look like what they mean. E.g., asterisks around a word actually
65 look like \*emphasis\*. Markdown lists look like, well, lists. Even
66 blockquotes look like quoted passages of text, assuming you've ever
71 <h3 id="html">Inline HTML</h3>
73 Markdown's syntax is intended for one purpose: to be used as a
74 format for *writing* for the web.
76 Markdown is not a replacement for HTML, or even close to it. Its
77 syntax is very small, corresponding only to a very small subset of
78 HTML tags. The idea is *not* to create a syntax that makes it easier
79 to insert HTML tags. In my opinion, HTML tags are already easy to
80 insert. The idea for Markdown is to make it easy to read, write, and
81 edit prose. HTML is a *publishing* format; Markdown is a *writing*
82 format. Thus, Markdown's formatting syntax only addresses issues that
83 can be conveyed in plain text.
85 For any markup that is not covered by Markdown's syntax, you simply
86 use HTML itself. There's no need to preface it or delimit it to
87 indicate that you're switching from Markdown to HTML; you just use
90 The only restrictions are that block-level HTML elements -- e.g. `<div>`,
91 `<table>`, `<pre>`, `<p>`, etc. -- must be separated from surrounding
92 content by blank lines, and the start and end tags of the block should
93 not be indented with tabs or spaces. Markdown is smart enough not
94 to add extra (unwanted) `<p>` tags around HTML block-level tags.
96 For example, to add an HTML table to a Markdown article:
98 This is a regular paragraph.
106 This is another regular paragraph.
108 Note that Markdown formatting syntax is not processed within block-level
109 HTML tags. E.g., you can't use Markdown-style `*emphasis*` inside an
112 Span-level HTML tags -- e.g. `<span>`, `<cite>`, or `<del>` -- can be
113 used anywhere in a Markdown paragraph, list item, or header. If you
114 want, you can even use HTML tags instead of Markdown formatting; e.g. if
115 you'd prefer to use HTML `<a>` or `<img>` tags instead of Markdown's
116 link or image syntax, go right ahead.
118 Unlike block-level HTML tags, Markdown syntax *is* processed within
122 <h3 id="autoescape">Automatic Escaping for Special Characters</h3>
124 In HTML, there are two characters that demand special treatment: `<`
125 and `&`. Left angle brackets are used to start tags; ampersands are
126 used to denote HTML entities. If you want to use them as literal
127 characters, you must escape them as entities, e.g. `<`, and
130 Ampersands in particular are bedeviling for web writers. If you want to
131 write about 'AT&T', you need to write '`AT&T`'. You even need to
132 escape ampersands within URLs. Thus, if you want to link to:
134 http://images.google.com/images?num=30&q=larry+bird
136 you need to encode the URL as:
138 http://images.google.com/images?num=30&q=larry+bird
140 in your anchor tag `href` attribute. Needless to say, this is easy to
141 forget, and is probably the single most common source of HTML validation
142 errors in otherwise well-marked-up web sites.
144 Markdown allows you to use these characters naturally, taking care of
145 all the necessary escaping for you. If you use an ampersand as part of
146 an HTML entity, it remains unchanged; otherwise it will be translated
149 So, if you want to include a copyright symbol in your article, you can write:
153 and Markdown will leave it alone. But if you write:
157 Markdown will translate it to:
161 Similarly, because Markdown supports [inline HTML](#html), if you use
162 angle brackets as delimiters for HTML tags, Markdown will treat them as
163 such. But if you write:
167 Markdown will translate it to:
171 However, inside Markdown code spans and blocks, angle brackets and
172 ampersands are *always* encoded automatically. This makes it easy to use
173 Markdown to write about HTML code. (As opposed to raw HTML, which is a
174 terrible format for writing about HTML syntax, because every single `<`
175 and `&` in your example code needs to be escaped.)
181 <h2 id="block">Block Elements</h2>
184 <h3 id="p">Paragraphs and Line Breaks</h3>
186 A paragraph is simply one or more consecutive lines of text, separated
187 by one or more blank lines. (A blank line is any line that looks like a
188 blank line -- a line containing nothing but spaces or tabs is considered
189 blank.) Normal paragraphs should not be indented with spaces or tabs.
191 The implication of the "one or more consecutive lines of text" rule is
192 that Markdown supports "hard-wrapped" text paragraphs. This differs
193 significantly from most other text-to-HTML formatters (including Movable
194 Type's "Convert Line Breaks" option) which translate every line break
195 character in a paragraph into a `<br />` tag.
197 When you *do* want to insert a `<br />` break tag using Markdown, you
198 end a line with two or more spaces, then type return.
200 Yes, this takes a tad more effort to create a `<br />`, but a simplistic
201 "every line break is a `<br />`" rule wouldn't work for Markdown.
202 Markdown's email-style [blockquoting][bq] and multi-paragraph [list items][l]
203 work best -- and look better -- when you format them with hard breaks.
210 <h3 id="header">Headers</h3>
212 Markdown supports two styles of headers, [Setext] [1] and [atx] [2].
214 Setext-style headers are "underlined" using equal signs (for first-level
215 headers) and dashes (for second-level headers). For example:
223 Any number of underlining `=`'s or `-`'s will work.
225 Atx-style headers use 1-6 hash characters at the start of the line,
226 corresponding to header levels 1-6. For example:
234 Optionally, you may "close" atx-style headers. This is purely
235 cosmetic -- you can use this if you think it looks better. The
236 closing hashes don't even need to match the number of hashes
237 used to open the header. (The number of opening hashes
238 determines the header level.) :
244 ### This is an H3 ######
247 <h3 id="blockquote">Blockquotes</h3>
249 Markdown uses email-style `>` characters for blockquoting. If you're
250 familiar with quoting passages of text in an email message, then you
251 know how to create a blockquote in Markdown. It looks best if you hard
252 wrap the text and put a `>` before every line:
254 > This is a blockquote with two paragraphs. Lorem ipsum dolor sit amet,
255 > consectetuer adipiscing elit. Aliquam hendrerit mi posuere lectus.
256 > Vestibulum enim wisi, viverra nec, fringilla in, laoreet vitae, risus.
258 > Donec sit amet nisl. Aliquam semper ipsum sit amet velit. Suspendisse
259 > id sem consectetuer libero luctus adipiscing.
261 Markdown allows you to be lazy and only put the `>` before the first
262 line of a hard-wrapped paragraph:
264 > This is a blockquote with two paragraphs. Lorem ipsum dolor sit amet,
265 consectetuer adipiscing elit. Aliquam hendrerit mi posuere lectus.
266 Vestibulum enim wisi, viverra nec, fringilla in, laoreet vitae, risus.
268 > Donec sit amet nisl. Aliquam semper ipsum sit amet velit. Suspendisse
269 id sem consectetuer libero luctus adipiscing.
271 Blockquotes can be nested (i.e. a blockquote-in-a-blockquote) by
272 adding additional levels of `>`:
274 > This is the first level of quoting.
276 > > This is nested blockquote.
278 > Back to the first level.
280 Blockquotes can contain other Markdown elements, including headers, lists,
283 > ## This is a header.
285 > 1. This is the first list item.
286 > 2. This is the second list item.
288 > Here's some example code:
290 > return shell_exec("echo $input | $markdown_script");
292 Any decent text editor should make email-style quoting easy. For
293 example, with BBEdit, you can make a selection and choose Increase
294 Quote Level from the Text menu.
297 <h3 id="list">Lists</h3>
299 Markdown supports ordered (numbered) and unordered (bulleted) lists.
301 Unordered lists use asterisks, pluses, and hyphens -- interchangeably
320 Ordered lists use numbers followed by periods:
326 It's important to note that the actual numbers you use to mark the
327 list have no effect on the HTML output Markdown produces. The HTML
328 Markdown produces from the above list is:
336 If you instead wrote the list in Markdown like this:
348 you'd get the exact same HTML output. The point is, if you want to,
349 you can use ordinal numbers in your ordered Markdown lists, so that
350 the numbers in your source match the numbers in your published HTML.
351 But if you want to be lazy, you don't have to.
353 If you do use lazy list numbering, however, you should still start the
354 list with the number 1. At some point in the future, Markdown may support
355 starting ordered lists at an arbitrary number.
357 List markers typically start at the left margin, but may be indented by
358 up to three spaces. List markers must be followed by one or more spaces
361 To make lists look nice, you can wrap items with hanging indents:
363 * Lorem ipsum dolor sit amet, consectetuer adipiscing elit.
364 Aliquam hendrerit mi posuere lectus. Vestibulum enim wisi,
365 viverra nec, fringilla in, laoreet vitae, risus.
366 * Donec sit amet nisl. Aliquam semper ipsum sit amet velit.
367 Suspendisse id sem consectetuer libero luctus adipiscing.
369 But if you want to be lazy, you don't have to:
371 * Lorem ipsum dolor sit amet, consectetuer adipiscing elit.
372 Aliquam hendrerit mi posuere lectus. Vestibulum enim wisi,
373 viverra nec, fringilla in, laoreet vitae, risus.
374 * Donec sit amet nisl. Aliquam semper ipsum sit amet velit.
375 Suspendisse id sem consectetuer libero luctus adipiscing.
377 If list items are separated by blank lines, Markdown will wrap the
378 items in `<p>` tags in the HTML output. For example, this input:
400 <li><p>Magic</p></li>
403 List items may consist of multiple paragraphs. Each subsequent
404 paragraph in a list item must be indented by either 4 spaces
407 1. This is a list item with two paragraphs. Lorem ipsum dolor
408 sit amet, consectetuer adipiscing elit. Aliquam hendrerit
411 Vestibulum enim wisi, viverra nec, fringilla in, laoreet
412 vitae, risus. Donec sit amet nisl. Aliquam semper ipsum
415 2. Suspendisse id sem consectetuer libero luctus adipiscing.
417 It looks nice if you indent every line of the subsequent
418 paragraphs, but here again, Markdown will allow you to be
421 * This is a list item with two paragraphs.
423 This is the second paragraph in the list item. You're
424 only required to indent the first line. Lorem ipsum dolor
425 sit amet, consectetuer adipiscing elit.
427 * Another item in the same list.
429 To put a blockquote within a list item, the blockquote's `>`
430 delimiters need to be indented:
432 * A list item with a blockquote:
434 > This is a blockquote
435 > inside a list item.
437 To put a code block within a list item, the code block needs
438 to be indented *twice* -- 8 spaces or two tabs:
440 * A list item with a code block:
445 It's worth noting that it's possible to trigger an ordered list by
446 accident, by writing something like this:
448 1986. What a great season.
450 In other words, a *number-period-space* sequence at the beginning of a
451 line. To avoid this, you can backslash-escape the period:
453 1986\. What a great season.
457 <h3 id="precode">Code Blocks</h3>
459 Pre-formatted code blocks are used for writing about programming or
460 markup source code. Rather than forming normal paragraphs, the lines
461 of a code block are interpreted literally. Markdown wraps a code block
462 in both `<pre>` and `<code>` tags.
464 To produce a code block in Markdown, simply indent every line of the
465 block by at least 4 spaces or 1 tab. For example, given this input:
467 This is a normal paragraph:
469 This is a code block.
471 Markdown will generate:
473 <p>This is a normal paragraph:</p>
475 <pre><code>This is a code block.
478 One level of indentation -- 4 spaces or 1 tab -- is removed from each
479 line of the code block. For example, this:
481 Here is an example of AppleScript:
483 tell application "Foo"
489 <p>Here is an example of AppleScript:</p>
491 <pre><code>tell application "Foo"
496 A code block continues until it reaches a line that is not indented
497 (or the end of the article).
499 Within a code block, ampersands (`&`) and angle brackets (`<` and `>`)
500 are automatically converted into HTML entities. This makes it very
501 easy to include example HTML source code using Markdown -- just paste
502 it and indent it, and Markdown will handle the hassle of encoding the
503 ampersands and angle brackets. For example, this:
506 © 2004 Foo Corporation
511 <pre><code><div class="footer">
512 &copy; 2004 Foo Corporation
516 Regular Markdown syntax is not processed within code blocks. E.g.,
517 asterisks are just literal asterisks within a code block. This means
518 it's also easy to use Markdown to write about Markdown's own syntax.
522 <h3 id="hr">Horizontal Rules</h3>
524 You can produce a horizontal rule tag (`<hr />`) by placing three or
525 more hyphens, asterisks, or underscores on a line by themselves. If you
526 wish, you may use spaces between the hyphens or asterisks. Each of the
527 following lines will produce a horizontal rule:
537 ---------------------------------------
542 <h2 id="span">Span Elements</h2>
544 <h3 id="link">Links</h3>
546 Markdown supports two style of links: *inline* and *reference*.
548 In both styles, the link text is delimited by [square brackets].
550 To create an inline link, use a set of regular parentheses immediately
551 after the link text's closing square bracket. Inside the parentheses,
552 put the URL where you want the link to point, along with an *optional*
553 title for the link, surrounded in quotes. For example:
555 This is [an example](http://example.com/ "Title") inline link.
557 [This link](http://example.net/) has no title attribute.
561 <p>This is <a href="http://example.com/" title="Title">
562 an example</a> inline link.</p>
564 <p><a href="http://example.net/">This link</a> has no
567 If you're referring to a local resource on the same server, you can
570 See my [About](/about/) page for details.
572 Reference-style links use a second set of square brackets, inside
573 which you place a label of your choosing to identify the link:
575 This is [an example][id] reference-style link.
577 You can optionally use a space to separate the sets of brackets:
579 This is [an example] [id] reference-style link.
581 Then, anywhere in the document, you define your link label like this,
584 [id]: http://example.com/ "Optional Title Here"
588 * Square brackets containing the link identifier (optionally
589 indented from the left margin using up to three spaces);
590 * followed by a colon;
591 * followed by one or more spaces (or tabs);
592 * followed by the URL for the link;
593 * optionally followed by a title attribute for the link, enclosed
594 in double or single quotes, or enclosed in parentheses.
596 The following three link definitions are equivalent:
598 [foo]: http://example.com/ "Optional Title Here"
599 [foo]: http://example.com/ 'Optional Title Here'
600 [foo]: http://example.com/ (Optional Title Here)
602 **Note:** There is a known bug in Markdown.pl 1.0.1 which prevents
603 single quotes from being used to delimit link titles.
605 The link URL may, optionally, be surrounded by angle brackets:
607 [id]: <http://example.com/> "Optional Title Here"
609 You can put the title attribute on the next line and use extra spaces
610 or tabs for padding, which tends to look better with longer URLs:
612 [id]: http://example.com/longish/path/to/resource/here
613 "Optional Title Here"
615 Link definitions are only used for creating links during Markdown
616 processing, and are stripped from your document in the HTML output.
618 Link definition names may consist of letters, numbers, spaces, and
619 punctuation -- but they are *not* case sensitive. E.g. these two
627 The *implicit link name* shortcut allows you to omit the name of the
628 link, in which case the link text itself is used as the name.
629 Just use an empty set of square brackets -- e.g., to link the word
630 "Google" to the google.com web site, you could simply write:
634 And then define the link:
636 [Google]: http://google.com/
638 Because link names may contain spaces, this shortcut even works for
639 multiple words in the link text:
641 Visit [Daring Fireball][] for more information.
643 And then define the link:
645 [Daring Fireball]: http://daringfireball.net/
647 Link definitions can be placed anywhere in your Markdown document. I
648 tend to put them immediately after each paragraph in which they're
649 used, but if you want, you can put them all at the end of your
650 document, sort of like footnotes.
652 Here's an example of reference links in action:
654 I get 10 times more traffic from [Google] [1] than from
655 [Yahoo] [2] or [MSN] [3].
657 [1]: http://google.com/ "Google"
658 [2]: http://search.yahoo.com/ "Yahoo Search"
659 [3]: http://search.msn.com/ "MSN Search"
661 Using the implicit link name shortcut, you could instead write:
663 I get 10 times more traffic from [Google][] than from
664 [Yahoo][] or [MSN][].
666 [google]: http://google.com/ "Google"
667 [yahoo]: http://search.yahoo.com/ "Yahoo Search"
668 [msn]: http://search.msn.com/ "MSN Search"
670 Both of the above examples will produce the following HTML output:
672 <p>I get 10 times more traffic from <a href="http://google.com/"
673 title="Google">Google</a> than from
674 <a href="http://search.yahoo.com/" title="Yahoo Search">Yahoo</a>
675 or <a href="http://search.msn.com/" title="MSN Search">MSN</a>.</p>
677 For comparison, here is the same paragraph written using
678 Markdown's inline link style:
680 I get 10 times more traffic from [Google](http://google.com/ "Google")
681 than from [Yahoo](http://search.yahoo.com/ "Yahoo Search") or
682 [MSN](http://search.msn.com/ "MSN Search").
684 The point of reference-style links is not that they're easier to
685 write. The point is that with reference-style links, your document
686 source is vastly more readable. Compare the above examples: using
687 reference-style links, the paragraph itself is only 81 characters
688 long; with inline-style links, it's 176 characters; and as raw HTML,
689 it's 234 characters. In the raw HTML, there's more markup than there
692 With Markdown's reference-style links, a source document much more
693 closely resembles the final output, as rendered in a browser. By
694 allowing you to move the markup-related metadata out of the paragraph,
695 you can add links without interrupting the narrative flow of your
699 <h3 id="em">Emphasis</h3>
701 Markdown treats asterisks (`*`) and underscores (`_`) as indicators of
702 emphasis. Text wrapped with one `*` or `_` will be wrapped with an
703 HTML `<em>` tag; double `*`'s or `_`'s will be wrapped with an HTML
704 `<strong>` tag. E.g., this input:
712 __double underscores__
716 <em>single asterisks</em>
718 <em>single underscores</em>
720 <strong>double asterisks</strong>
722 <strong>double underscores</strong>
724 You can use whichever style you prefer; the lone restriction is that
725 the same character must be used to open and close an emphasis span.
727 Emphasis can be used in the middle of a word:
729 un*frigging*believable
731 But if you surround an `*` or `_` with spaces, it'll be treated as a
732 literal asterisk or underscore.
734 To produce a literal asterisk or underscore at a position where it
735 would otherwise be used as an emphasis delimiter, you can backslash
738 \*this text is surrounded by literal asterisks\*
742 <h3 id="code">Code</h3>
744 To indicate a span of code, wrap it with backtick quotes (`` ` ``).
745 Unlike a pre-formatted code block, a code span indicates code within a
746 normal paragraph. For example:
748 Use the `printf()` function.
752 <p>Use the <code>printf()</code> function.</p>
754 To include a literal backtick character within a code span, you can use
755 multiple backticks as the opening and closing delimiters:
757 ``There is a literal backtick (`) here.``
759 which will produce this:
761 <p><code>There is a literal backtick (`) here.</code></p>
763 The backtick delimiters surrounding a code span may include spaces --
764 one after the opening, one before the closing. This allows you to place
765 literal backtick characters at the beginning or end of a code span:
767 A single backtick in a code span: `` ` ``
769 A backtick-delimited string in a code span: `` `foo` ``
773 <p>A single backtick in a code span: <code>`</code></p>
775 <p>A backtick-delimited string in a code span: <code>`foo`</code></p>
777 With a code span, ampersands and angle brackets are encoded as HTML
778 entities automatically, which makes it easy to include example HTML
779 tags. Markdown will turn this:
781 Please don't use any `<blink>` tags.
785 <p>Please don't use any <code><blink></code> tags.</p>
789 `—` is the decimal-encoded equivalent of `—`.
793 <p><code>&#8212;</code> is the decimal-encoded
794 equivalent of <code>&mdash;</code>.</p>
798 <h3 id="img">Images</h3>
800 Admittedly, it's fairly difficult to devise a "natural" syntax for
801 placing images into a plain text document format.
803 Markdown uses an image syntax that is intended to resemble the syntax
804 for links, allowing for two styles: *inline* and *reference*.
806 Inline image syntax looks like this:
808 ![Alt text](/path/to/img.jpg)
810 ![Alt text](/path/to/img.jpg "Optional title")
814 * An exclamation mark: `!`;
815 * followed by a set of square brackets, containing the `alt`
816 attribute text for the image;
817 * followed by a set of parentheses, containing the URL or path to
818 the image, and an optional `title` attribute enclosed in double
821 Reference-style image syntax looks like this:
825 Where "id" is the name of a defined image reference. Image references
826 are defined using syntax identical to link references:
828 [id]: url/to/image "Optional title attribute"
830 As of this writing, Markdown has no syntax for specifying the
831 dimensions of an image; if this is important to you, you can simply
832 use regular HTML `<img>` tags.
838 <h2 id="misc">Miscellaneous</h2>
840 <h3 id="autolink">Automatic Links</h3>
842 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:
844 <http://example.com/>
846 Markdown will turn this into:
848 <a href="http://example.com/">http://example.com/</a>
850 Automatic links for email addresses work similarly, except that
851 Markdown will also perform a bit of randomized decimal and hex
852 entity-encoding to help obscure your address from address-harvesting
853 spambots. For example, Markdown will turn this:
855 <address@example.com>
857 into something like this:
859 <a href="mailto:addre
860 ss@example.co
861 m">address@exa
862 mple.com</a>
864 which will render in a browser as a clickable link to "address@example.com".
866 (This sort of entity-encoding trick will indeed fool many, if not
867 most, address-harvesting bots, but it definitely won't fool all of
868 them. It's better than nothing, but an address published in this way
869 will probably eventually start receiving spam.)
873 <h3 id="backslash">Backslash Escapes</h3>
875 Markdown allows you to use backslash escapes to generate literal
876 characters which would otherwise have special meaning in Markdown's
877 formatting syntax. For example, if you wanted to surround a word
878 with literal asterisks (instead of an HTML `<em>` tag), you can use
879 backslashes before the asterisks, like this:
881 \*literal asterisks\*
883 Markdown provides backslash escapes for the following characters:
894 - minus sign (hyphen)