3 caption: This Markdown is Tested!
10 <ul id="ProjectSubmenu">
11 <li><a href="/projects/markdown/" title="Markdown Project Page">Main</a></li>
12 <li><a href="/projects/markdown/basics" title="Markdown Basics">Basics</a></li>
13 <li><a class="selected" title="Markdown Syntax Documentation">Syntax</a></li>
14 <li><a href="/projects/markdown/license" title="Pricing and License Information">License</a></li>
15 <li><a href="/projects/markdown/dingus" title="Online Markdown Web Form">Dingus</a></li>
19 * [Overview](#overview)
20 * [Philosophy](#philosophy)
21 * [Inline HTML](#html)
22 * [Automatic Escaping for Special Characters](#autoescape)
23 * [Block Elements](#block)
24 * [Paragraphs and Line Breaks](#p)
26 * [Blockquotes](#blockquote)
28 * [Code Blocks](#precode)
29 * [Horizontal Rules](#hr)
30 * [Span Elements](#span)
35 * [Miscellaneous](#misc)
36 * [Backslash Escapes](#backslash)
37 * [Automatic Links](#autolink)
40 **Note:** This document is itself written using Markdown; you
41 can [see the source for it by adding '.text' to the URL][src].
43 [src]: /projects/markdown/syntax.text
47 <h2 id="overview">Overview</h2>
49 <h3 id="philosophy">Philosophy</h3>
51 Markdown is intended to be as easy-to-read and easy-to-write as is feasible.
53 Readability, however, is emphasized above all else. A Markdown-formatted
54 document should be publishable as-is, as plain text, without looking
55 like it's been marked up with tags or formatting instructions. While
56 Markdown's syntax has been influenced by several existing text-to-HTML
57 filters -- including [Setext] [1], [atx] [2], [Textile] [3], [reStructuredText] [4],
58 [Grutatext] [5], and [EtText] [6] -- the single biggest source of
59 inspiration for Markdown's syntax is the format of plain text email.
61 [1]: http://docutils.sourceforge.net/mirror/setext.html
62 [2]: http://www.aaronsw.com/2002/atx/
63 [3]: http://textism.com/tools/textile/
64 [4]: http://docutils.sourceforge.net/rst.html
65 [5]: http://www.triptico.com/software/grutatxt.html
66 [6]: http://ettext.taint.org/doc/
68 To this end, Markdown's syntax is comprised entirely of punctuation
69 characters, which punctuation characters have been carefully chosen so
70 as to look like what they mean. E.g., asterisks around a word actually
71 look like \*emphasis\*. Markdown lists look like, well, lists. Even
72 blockquotes look like quoted passages of text, assuming you've ever
77 <h3 id="html">Inline HTML</h3>
79 Markdown's syntax is intended for one purpose: to be used as a
80 format for *writing* for the web.
82 Markdown is not a replacement for HTML, or even close to it. Its
83 syntax is very small, corresponding only to a very small subset of
84 HTML tags. The idea is *not* to create a syntax that makes it easier
85 to insert HTML tags. In my opinion, HTML tags are already easy to
86 insert. The idea for Markdown is to make it easy to read, write, and
87 edit prose. HTML is a *publishing* format; Markdown is a *writing*
88 format. Thus, Markdown's formatting syntax only addresses issues that
89 can be conveyed in plain text.
91 For any markup that is not covered by Markdown's syntax, you simply
92 use HTML itself. There's no need to preface it or delimit it to
93 indicate that you're switching from Markdown to HTML; you just use
96 The only restrictions are that block-level HTML elements -- e.g. `<div>`,
97 `<table>`, `<pre>`, `<p>`, etc. -- must be separated from surrounding
98 content by blank lines, and the start and end tags of the block should
99 not be indented with tabs or spaces. Markdown is smart enough not
100 to add extra (unwanted) `<p>` tags around HTML block-level tags.
102 For example, to add an HTML table to a Markdown article:
104 This is a regular paragraph.
112 This is another regular paragraph.
114 Note that Markdown formatting syntax is not processed within block-level
115 HTML tags. E.g., you can't use Markdown-style `*emphasis*` inside an
118 Span-level HTML tags -- e.g. `<span>`, `<cite>`, or `<del>` -- can be
119 used anywhere in a Markdown paragraph, list item, or header. If you
120 want, you can even use HTML tags instead of Markdown formatting; e.g. if
121 you'd prefer to use HTML `<a>` or `<img>` tags instead of Markdown's
122 link or image syntax, go right ahead.
124 Unlike block-level HTML tags, Markdown syntax *is* processed within
128 <h3 id="autoescape">Automatic Escaping for Special Characters</h3>
130 In HTML, there are two characters that demand special treatment: `<`
131 and `&`. Left angle brackets are used to start tags; ampersands are
132 used to denote HTML entities. If you want to use them as literal
133 characters, you must escape them as entities, e.g. `<`, and
136 Ampersands in particular are bedeviling for web writers. If you want to
137 write about 'AT&T', you need to write '`AT&T`'. You even need to
138 escape ampersands within URLs. Thus, if you want to link to:
140 http://images.google.com/images?num=30&q=larry+bird
142 you need to encode the URL as:
144 http://images.google.com/images?num=30&q=larry+bird
146 in your anchor tag `href` attribute. Needless to say, this is easy to
147 forget, and is probably the single most common source of HTML validation
148 errors in otherwise well-marked-up web sites.
150 Markdown allows you to use these characters naturally, taking care of
151 all the necessary escaping for you. If you use an ampersand as part of
152 an HTML entity, it remains unchanged; otherwise it will be translated
155 So, if you want to include a copyright symbol in your article, you can write:
159 and Markdown will leave it alone. But if you write:
163 Markdown will translate it to:
167 Similarly, because Markdown supports [inline HTML](#html), if you use
168 angle brackets as delimiters for HTML tags, Markdown will treat them as
169 such. But if you write:
173 Markdown will translate it to:
177 However, inside Markdown code spans and blocks, angle brackets and
178 ampersands are *always* encoded automatically. This makes it easy to use
179 Markdown to write about HTML code. (As opposed to raw HTML, which is a
180 terrible format for writing about HTML syntax, because every single `<`
181 and `&` in your example code needs to be escaped.)
187 <h2 id="block">Block Elements</h2>
190 <h3 id="p">Paragraphs and Line Breaks</h3>
192 A paragraph is simply one or more consecutive lines of text, separated
193 by one or more blank lines. (A blank line is any line that looks like a
194 blank line -- a line containing nothing but spaces or tabs is considered
195 blank.) Normal paragraphs should not be intended with spaces or tabs.
197 The implication of the "one or more consecutive lines of text" rule is
198 that Markdown supports "hard-wrapped" text paragraphs. This differs
199 significantly from most other text-to-HTML formatters (including Movable
200 Type's "Convert Line Breaks" option) which translate every line break
201 character in a paragraph into a `<br />` tag.
203 When you *do* want to insert a `<br />` break tag using Markdown, you
204 end a line with two or more spaces, then type return.
206 Yes, this takes a tad more effort to create a `<br />`, but a simplistic
207 "every line break is a `<br />`" rule wouldn't work for Markdown.
208 Markdown's email-style [blockquoting][bq] and multi-paragraph [list items][l]
209 work best -- and look better -- when you format them with hard breaks.
216 <h3 id="header">Headers</h3>
218 Markdown supports two styles of headers, [Setext] [1] and [atx] [2].
220 Setext-style headers are "underlined" using equal signs (for first-level
221 headers) and dashes (for second-level headers). For example:
229 Any number of underlining `=`'s or `-`'s will work.
231 Atx-style headers use 1-6 hash characters at the start of the line,
232 corresponding to header levels 1-6. For example:
240 Optionally, you may "close" atx-style headers. This is purely
241 cosmetic -- you can use this if you think it looks better. The
242 closing hashes don't even need to match the number of hashes
243 used to open the header. (The number of opening hashes
244 determines the header level.) :
250 ### This is an H3 ######
253 <h3 id="blockquote">Blockquotes</h3>
255 Markdown uses email-style `>` characters for blockquoting. If you're
256 familiar with quoting passages of text in an email message, then you
257 know how to create a blockquote in Markdown. It looks best if you hard
258 wrap the text and put a `>` before every line:
260 > This is a blockquote with two paragraphs. Lorem ipsum dolor sit amet,
261 > consectetuer adipiscing elit. Aliquam hendrerit mi posuere lectus.
262 > Vestibulum enim wisi, viverra nec, fringilla in, laoreet vitae, risus.
264 > Donec sit amet nisl. Aliquam semper ipsum sit amet velit. Suspendisse
265 > id sem consectetuer libero luctus adipiscing.
267 Markdown allows you to be lazy and only put the `>` before the first
268 line of a hard-wrapped paragraph:
270 > This is a blockquote with two paragraphs. Lorem ipsum dolor sit amet,
271 consectetuer adipiscing elit. Aliquam hendrerit mi posuere lectus.
272 Vestibulum enim wisi, viverra nec, fringilla in, laoreet vitae, risus.
274 > Donec sit amet nisl. Aliquam semper ipsum sit amet velit. Suspendisse
275 id sem consectetuer libero luctus adipiscing.
277 Blockquotes can be nested (i.e. a blockquote-in-a-blockquote) by
278 adding additional levels of `>`:
280 > This is the first level of quoting.
282 > > This is nested blockquote.
284 > Back to the first level.
286 Blockquotes can contain other Markdown elements, including headers, lists,
289 > ## This is a header.
291 > 1. This is the first list item.
292 > 2. This is the second list item.
294 > Here's some example code:
296 > return shell_exec("echo $input | $markdown_script");
298 Any decent text editor should make email-style quoting easy. For
299 example, with BBEdit, you can make a selection and choose Increase
300 Quote Level from the Text menu.
303 <h3 id="list">Lists</h3>
305 Markdown supports ordered (numbered) and unordered (bulleted) lists.
307 Unordered lists use asterisks, pluses, and hyphens -- interchangably
326 Ordered lists use numbers followed by periods:
332 It's important to note that the actual numbers you use to mark the
333 list have no effect on the HTML output Markdown produces. The HTML
334 Markdown produces from the above list is:
342 If you instead wrote the list in Markdown like this:
354 you'd get the exact same HTML output. The point is, if you want to,
355 you can use ordinal numbers in your ordered Markdown lists, so that
356 the numbers in your source match the numbers in your published HTML.
357 But if you want to be lazy, you don't have to.
359 If you do use lazy list numbering, however, you should still start the
360 list with the number 1. At some point in the future, Markdown may support
361 starting ordered lists at an arbitrary number.
363 List markers typically start at the left margin, but may be indented by
364 up to three spaces. List markers must be followed by one or more spaces
367 To make lists look nice, you can wrap items with hanging indents:
369 * Lorem ipsum dolor sit amet, consectetuer adipiscing elit.
370 Aliquam hendrerit mi posuere lectus. Vestibulum enim wisi,
371 viverra nec, fringilla in, laoreet vitae, risus.
372 * Donec sit amet nisl. Aliquam semper ipsum sit amet velit.
373 Suspendisse id sem consectetuer libero luctus adipiscing.
375 But if you want to be lazy, you don't have to:
377 * Lorem ipsum dolor sit amet, consectetuer adipiscing elit.
378 Aliquam hendrerit mi posuere lectus. Vestibulum enim wisi,
379 viverra nec, fringilla in, laoreet vitae, risus.
380 * Donec sit amet nisl. Aliquam semper ipsum sit amet velit.
381 Suspendisse id sem consectetuer libero luctus adipiscing.
383 If list items are separated by blank lines, Markdown will wrap the
384 items in `<p>` tags in the HTML output. For example, this input:
406 <li><p>Magic</p></li>
409 List items may consist of multiple paragraphs. Each subsequent
410 paragraph in a list item must be intended by either 4 spaces
413 1. This is a list item with two paragraphs. Lorem ipsum dolor
414 sit amet, consectetuer adipiscing elit. Aliquam hendrerit
417 Vestibulum enim wisi, viverra nec, fringilla in, laoreet
418 vitae, risus. Donec sit amet nisl. Aliquam semper ipsum
421 2. Suspendisse id sem consectetuer libero luctus adipiscing.
423 It looks nice if you indent every line of the subsequent
424 paragraphs, but here again, Markdown will allow you to be
427 * This is a list item with two paragraphs.
429 This is the second paragraph in the list item. You're
430 only required to indent the first line. Lorem ipsum dolor
431 sit amet, consectetuer adipiscing elit.
433 * Another item in the same list.
435 To put a blockquote within a list item, the blockquote's `>`
436 delimiters need to be indented:
438 * A list item with a blockquote:
440 > This is a blockquote
441 > inside a list item.
443 To put a code block within a list item, the code block needs
444 to be indented *twice* -- 8 spaces or two tabs:
446 * A list item with a code block:
451 It's worth noting that it's possible to trigger an ordered list by
452 accident, by writing something like this:
454 1986. What a great season.
456 In other words, a *number-period-space* sequence at the beginning of a
457 line. To avoid this, you can backslash-escape the period:
459 1986\. What a great season.
463 <h3 id="precode">Code Blocks</h3>
465 Pre-formatted code blocks are used for writing about programming or
466 markup source code. Rather than forming normal paragraphs, the lines
467 of a code block are interpreted literally. Markdown wraps a code block
468 in both `<pre>` and `<code>` tags.
470 To produce a code block in Markdown, simply indent every line of the
471 block by at least 4 spaces or 1 tab. For example, given this input:
473 This is a normal paragraph:
475 This is a code block.
477 Markdown will generate:
479 <p>This is a normal paragraph:</p>
481 <pre><code>This is a code block.
484 One level of indentation -- 4 spaces or 1 tab -- is removed from each
485 line of the code block. For example, this:
487 Here is an example of AppleScript:
489 tell application "Foo"
495 <p>Here is an example of AppleScript:</p>
497 <pre><code>tell application "Foo"
502 A code block continues until it reaches a line that is not indented
503 (or the end of the article).
505 Within a code block, ampersands (`&`) and angle brackets (`<` and `>`)
506 are automatically converted into HTML entities. This makes it very
507 easy to include example HTML source code using Markdown -- just paste
508 it and indent it, and Markdown will handle the hassle of encoding the
509 ampersands and angle brackets. For example, this:
512 © 2004 Foo Corporation
517 <pre><code><div class="footer">
518 &copy; 2004 Foo Corporation
522 Regular Markdown syntax is not processed within code blocks. E.g.,
523 asterisks are just literal asterisks within a code block. This means
524 it's also easy to use Markdown to write about Markdown's own syntax.
528 <h3 id="hr">Horizontal Rules</h3>
530 You can produce a horizontal rule tag (`<hr />`) by placing three or
531 more hyphens, asterisks, or underscores on a line by themselves. If you
532 wish, you may use spaces between the hyphens or asterisks. Each of the
533 following lines will produce a horizontal rule:
543 ---------------------------------------
550 <h2 id="span">Span Elements</h2>
552 <h3 id="link">Links</h3>
554 Markdown supports two style of links: *inline* and *reference*.
556 In both styles, the link text is delimited by [square brackets].
558 To create an inline link, use a set of regular parentheses immediately
559 after the link text's closing square bracket. Inside the parentheses,
560 put the URL where you want the link to point, along with an *optional*
561 title for the link, surrounded in quotes. For example:
563 This is [an example](http://example.com/ "Title") inline link.
565 [This link](http://example.net/) has no title attribute.
569 <p>This is <a href="http://example.com/" title="Title">
570 an example</a> inline link.</p>
572 <p><a href="http://example.net/">This link</a> has no
575 If you're referring to a local resource on the same server, you can
578 See my [About](/about/) page for details.
580 Reference-style links use a second set of square brackets, inside
581 which you place a label of your choosing to identify the link:
583 This is [an example][id] reference-style link.
585 You can optionally use a space to separate the sets of brackets:
587 This is [an example] [id] reference-style link.
589 Then, anywhere in the document, you define your link label like this,
592 [id]: http://example.com/ "Optional Title Here"
596 * Square brackets containing the link identifier (optionally
597 indented from the left margin using up to three spaces);
598 * followed by a colon;
599 * followed by one or more spaces (or tabs);
600 * followed by the URL for the link;
601 * optionally followed by a title attribute for the link, enclosed
602 in double or single quotes.
604 The link URL may, optionally, be surrounded by angle brackets:
606 [id]: <http://example.com/> "Optional Title Here"
608 You can put the title attribute on the next line and use extra spaces
609 or tabs for padding, which tends to look better with longer URLs:
611 [id]: http://example.com/longish/path/to/resource/here
612 "Optional Title Here"
614 Link definitions are only used for creating links during Markdown
615 processing, and are stripped from your document in the HTML output.
617 Link definition names may constist of letters, numbers, spaces, and punctuation -- but they are *not* case sensitive. E.g. these two links:
624 The *implicit link name* shortcut allows you to omit the name of the
625 link, in which case the link text itself is used as the name.
626 Just use an empty set of square brackets -- e.g., to link the word
627 "Google" to the google.com web site, you could simply write:
631 And then define the link:
633 [Google]: http://google.com/
635 Because link names may contain spaces, this shortcut even works for
636 multiple words in the link text:
638 Visit [Daring Fireball][] for more information.
640 And then define the link:
642 [Daring Fireball]: http://daringfireball.net/
644 Link definitions can be placed anywhere in your Markdown document. I
645 tend to put them immediately after each paragraph in which they're
646 used, but if you want, you can put them all at the end of your
647 document, sort of like footnotes.
649 Here's an example of reference links in action:
651 I get 10 times more traffic from [Google] [1] than from
652 [Yahoo] [2] or [MSN] [3].
654 [1]: http://google.com/ "Google"
655 [2]: http://search.yahoo.com/ "Yahoo Search"
656 [3]: http://search.msn.com/ "MSN Search"
658 Using the implicit link name shortcut, you could instead write:
660 I get 10 times more traffic from [Google][] than from
661 [Yahoo][] or [MSN][].
663 [google]: http://google.com/ "Google"
664 [yahoo]: http://search.yahoo.com/ "Yahoo Search"
665 [msn]: http://search.msn.com/ "MSN Search"
667 Both of the above examples will produce the following HTML output:
669 <p>I get 10 times more traffic from <a href="http://google.com/"
670 title="Google">Google</a> than from
671 <a href="http://search.yahoo.com/" title="Yahoo Search">Yahoo</a>
672 or <a href="http://search.msn.com/" title="MSN Search">MSN</a>.</p>
674 For comparison, here is the same paragraph written using
675 Markdown's inline link style:
677 I get 10 times more traffic from [Google](http://google.com/ "Google")
678 than from [Yahoo](http://search.yahoo.com/ "Yahoo Search") or
679 [MSN](http://search.msn.com/ "MSN Search").
681 The point of reference-style links is not that they're easier to
682 write. The point is that with reference-style links, your document
683 source is vastly more readable. Compare the above examples: using
684 reference-style links, the paragraph itself is only 81 characters
685 long; with inline-style links, it's 176 characters; and as raw HTML,
686 it's 234 characters. In the raw HTML, there's more markup than there
689 With Markdown's reference-style links, a source document much more
690 closely resembles the final output, as rendered in a browser. By
691 allowing you to move the markup-related metadata out of the paragraph,
692 you can add links without interrupting the narrative flow of your
696 <h3 id="em">Emphasis</h3>
698 Markdown treats asterisks (`*`) and underscores (`_`) as indicators of
699 emphasis. Text wrapped with one `*` or `_` will be wrapped with an
700 HTML `<em>` tag; double `*`'s or `_`'s will be wrapped with an HTML
701 `<strong>` tag. E.g., this input:
709 __double underscores__
713 <em>single asterisks</em>
715 <em>single underscores</em>
717 <strong>double asterisks</strong>
719 <strong>double underscores</strong>
721 You can use whichever style you prefer; the lone restriction is that
722 the same character must be used to open and close an emphasis span.
724 Emphasis can be used in the middle of a word:
726 un*fucking*believable
728 But if you surround an `*` or `_` with spaces, it'll be treated as a
729 literal asterisk or underscore.
731 To produce a literal asterisk or underscore at a position where it
732 would otherwise be used as an emphasis delimiter, you can backslash
735 \*this text is surrounded by literal asterisks\*
739 <h3 id="code">Code</h3>
741 To indicate a span of code, wrap it with backtick quotes (`` ` ``).
742 Unlike a pre-formatted code block, a code span indicates code within a
743 normal paragraph. For example:
745 Use the `printf()` function.
749 <p>Use the <code>printf()</code> function.</p>
751 To include a literal backtick character within a code span, you can use
752 multiple backticks as the opening and closing delimiters:
754 ``There is a literal backtick (`) here.``
756 which will produce this:
758 <p><code>There is a literal backtick (`) here.</code></p>
760 The backtick delimiters surrounding a code span may include spaces --
761 one after the opening, one before the closing. This allows you to place
762 literal backtick characters at the beginning or end of a code span:
764 A single backtick in a code span: `` ` ``
766 A backtick-delimited string in a code span: `` `foo` ``
770 <p>A single backtick in a code span: <code>`</code></p>
772 <p>A backtick-delimited string in a code span: <code>`foo`</code></p>
774 With a code span, ampersands and angle brackets are encoded as HTML
775 entities automatically, which makes it easy to include example HTML
776 tags. Markdown will turn this:
778 Please don't use any `<blink>` tags.
782 <p>Please don't use any <code><blink></code> tags.</p>
786 `—` is the decimal-encoded equivalent of `—`.
790 <p><code>&#8212;</code> is the decimal-encoded
791 equivalent of <code>&mdash;</code>.</p>
795 <h3 id="img">Images</h3>
797 Admittedly, it's fairly difficult to devise a "natural" syntax for
798 placing images into a plain text document format.
800 Markdown uses an image syntax that is intended to resemble the syntax
801 for links, allowing for two styles: *inline* and *reference*.
803 Inline image syntax looks like this:
805 ![Alt text](/path/to/img.jpg)
807 ![Alt text](/path/to/img.jpg "Optional title")
811 * An exclamation mark: `!`;
812 * followed by a set of square brackets, containing the `alt`
813 attribute text for the image;
814 * followed by a set of parentheses, containing the URL or path to
815 the image, and an optional `title` attribute enclosed in double
818 Reference-style image syntax looks like this:
822 Where "id" is the name of a defined image reference. Image references
823 are defined using syntax identical to link references:
825 [id]: url/to/image "Optional title attribute"
827 As of this writing, Markdown has no syntax for specifying the
828 dimensions of an image; if this is important to you, you can simply
829 use regular HTML `<img>` tags.
835 <h2 id="misc">Miscellaneous</h2>
837 <h3 id="autolink">Automatic Links</h3>
839 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:
841 <http://example.com/>
843 Markdown will turn this into:
845 <a href="http://example.com/">http://example.com/</a>
847 Automatic links for email addresses work similarly, except that
848 Markdown will also perform a bit of randomized decimal and hex
849 entity-encoding to help obscure your address from address-harvesting
850 spambots. For example, Markdown will turn this:
852 <address@example.com>
854 into something like this:
856 <a href="mailto:addre
857 ss@example.co
858 m">address@exa
859 mple.com</a>
861 which will render in a browser as a clickable link to "address@example.com".
863 (This sort of entity-encoding trick will indeed fool many, if not
864 most, address-harvesting bots, but it definitely won't fool all of
865 them. It's better than nothing, but an address published in this way
866 will probably eventually start receiving spam.)
870 <h3 id="backslash">Backslash Escapes</h3>
872 Markdown allows you to use backslash escapes to generate literal
873 characters which would otherwise have special meaning in Markdown's
874 formatting syntax. For example, if you wanted to surround a word with
875 literal asterisks (instead of an HTML `<em>` tag), you can backslashes
876 before the asterisks, like this:
878 \*literal asterisks\*
880 Markdown provides backslash escapes for the following characters:
891 - minus sign (hyphen)