Features

Introduction

HackMD is a realtime, multiplatform collaborative markdown note editor.
This means that you can write notes with other people on your desktop, tablet or even on the phone.
You can sign-in via Facebook, Twitter, GitHub, or Dropbox in the homepage.

Note that this service is still in an early stage, and thus still has some issues.
Please report new issues in GitHub.
If you need instant help, please send us a Facebook message.
Thank you very much!

Workspace

Modes

Desktop & Tablet

Edit: See only the editor.
View: See only the result.
Both: See both in split view.

Mobile

View: See only the result.
Edit: See only the editor.

Image Upload:

You can upload an image simply by clicking on the camera button .
Alternatively, you can drag-n-drop an image into the editor. Even pasting images is possible!
This will automatically upload the image to imgur, nothing to worry. :tada:

Share Notes:

If you want to share an editable note, just copy the URL.
If you want to share a read-only note, simply press publish button and copy the URL.

Save a Note:

Currently, you can save to Dropbox or save an .md file locally.

Import Notes:

Similarly to the save feature, you can also import an .md file from Dropbox ,
or import content from your clipboard , and that can parse some html which might be useful :smiley:

Permissions:

It is possible to change the access permission to a note through the little button on the top right of the view.
There are four possible options:

Freely: Anyone can edit this note.
Editable: A signed-in user can edit this note.
Limited: People have to sign-in to view and edit this note.
Locked: Anyone can view this note but only the owner can edit it.
Protected: People have to sign-in to view this note but only owner can edit.
Private: Only the owner can view and edit this note.

Only the owner of the note can change the note's permissions.

Embed a Note:

Notes can be embedded as follows:

<iframe width="100%" height="500" src="https://hackmd.io/features" frameborder="0"></iframe>

Slide Mode:

You can use a special syntax to organize your note into slides.
After that, you can use the Slide Mode to make a presentation.
Visit the above link for details.

View

Table of Contents:

You can look at the bottom right section of the view area, there is a ToC button .
Pressing that button will show you a current Table of Contents, and will highlight which section you're at.
ToCs support up to three header levels.

Permalink

Every header will automatically add a permalink on the right side.
You can hover and click to anchor on it.

Edit:

Shortcut Keys:

Just like Sublime text, which is pretty quick and convenient.

For more infomation, see here.

Auto-Complete:

This editor provides full auto-complete hints in markdown.

• Emojis: type : to show hints.
• Code blocks: type ``` and plus a character to show hint. ```
• Headers: type # to show hint.
• Referrals: type [] to show hint.
• Externals: type {} to show hint.
• Images: type ! to show hint.

Title:

This will take the first level 1 header as the note title.

Tags:

Using tags as follows, the specified tags will show in your history.

tags: features cool updated

YAML Metadata

You can provide advanced note information to set the browser behavior (visit above link for details):

• robots: set web robots meta
• lang: set browser language
• dir: set text direction
• breaks: set to use line breaks
• GA: set to use Google Analytics
• disqus: set to use Disqus
• slideOptions: setup slide mode options

ToC:

Use the syntax [TOC] to embed table of content into your note.

[TOC]

Emoji

You can type any emoji like this :smile: :smiley: :cry: :wink:

See full emoji list here.

ToDo List:

• [ ] ToDos
  • [x] Buy some salad
  • [ ] Brush teeth
  • [x] Drink some water

Code Block:

We support many programming languages, use the auto complete function to see the entire list.

var s = "JavaScript syntax highlighting";
alert(s);
function $initHighlight(block, cls) {
  try {
    if (cls.search(/\bno\-highlight\b/) != -1)
      return process(block, true, 0x0F) + 
             ' class=""';
  } catch (e) {
    /* handle exception */
  }
  for (var i = 0 / 2; i < classes.length; i++) {
    if (checkCondition(classes[i]) === undefined)
      return /\d+[\s/]/g;
  }
}

If you want line numbers, type = after specifying the code block languagues.
Also, you can specify the start line number.
Like below, the line number starts from 101:

var s = "JavaScript syntax highlighting";
alert(s);
function $initHighlight(block, cls) {
  try {
    if (cls.search(/\bno\-highlight\b/) != -1)
      return process(block, true, 0x0F) + 
             ' class=""';
  } catch (e) {
    /* handle exception */
  }
  for (var i = 0 / 2; i < classes.length; i++) {
    if (checkCondition(classes[i]) === undefined)
      return /\d+[\s/]/g;
  }
}

Or you might want to continue the previous code block's line number, use =+

var s = "JavaScript syntax highlighting";
alert(s);

Somtimes you have a super long text without breaks. It's time to use ! to wrap your code.

When you’re a carpenter making a beautiful chest of drawers, you’re not going to use a piece of plywood on the back.

Blockquote Tags:

Using the syntax below to specifiy your name, time and color to vary the blockquotes.
[name=ChengHan Wu] [time=Sun, Jun 28, 2015 9:59 PM] [color=#907bf7]

Even support the nest blockquotes!
[name=ChengHan Wu] [time=Sun, Jun 28, 2015 10:00 PM] [color=red]

Externals

YouTube

{%youtube 1G4isv_Fylg %}

Vimeo

{%vimeo 124148255 %}

Gist

{%gist schacon/4277%}

SlideShare

{%slideshare briansolis/26-disruptive-technology-trends-2016-2018-56796196 %}

Speakerdeck

{%speakerdeck sugarenia/xxlcss-how-to-scale-css-and-keep-your-sanity %}

PDF

Caution: this might be blocked by your browser if not using an https URL.
{%pdf https://papers.nips.cc/paper/5346-sequence-to-sequence-learning-with-neural-networks.pdf %}

MathJax

You can render LaTeX mathematical expressions using MathJax, as on math.stackexchange.com:

The Gamma function satisfying $\Gamma(n) = (n-1)!\quad\forall n\in\mathbb N$ is via the Euler integral

$$
x = {-b \pm \sqrt{b^2-4ac} \over 2a}.
$$

$$
\Gamma(z) = \int_0^\infty t^{z-1}e{-t}dt,.
$$

More information about LaTeX mathematical expressions here.

UML Diagrams

Sequence Diagrams

You can render sequence diagrams like this:

Alice->Bob: Hello Bob, how are you?
Note right of Bob: Bob thinks
Bob-->Alice: I am good thanks!
Note left of Alice: Alice responds
Alice->Bob: Where have you been?

Flow Charts

Flow charts can be specified like this:

st=>start: Start
e=>end: End
op=>operation: My Operation
op2=>operation: lalala
cond=>condition: Yes or No?

st->op->op2->cond
cond(yes)->e
cond(no)->op2

Graphviz

digraph hierarchy {

                nodesep=1.0 // increases the separation between nodes
                
                node [color=Red,fontname=Courier,shape=box] //All nodes will this shape and colour
                edge [color=Blue, style=dashed] //All the lines look like this

                Headteacher->{Deputy1 Deputy2 BusinessManager}
                Deputy1->{Teacher1 Teacher2}
                BusinessManager->ITManager
                {rank=same;ITManager Teacher1 Teacher2}  // Put them on the same level
}

Mermaid

gantt
    title A Gantt Diagram

    section Section
    A task           :a1, 2014-01-01, 30d
    Another task     :after a1  , 20d
    section Another
    Task in sec      :2014-01-12  , 12d
    anther task      : 24d

Abc

X:1
T:Speed the Plough
M:4/4
C:Trad.
K:G
|:GABc dedB|dedB dedB|c2ec B2dB|c2A2 A2BA|
GABc dedB|dedB dedB|c2ec B2dB|A2F2 G4:|
|:g2gf gdBd|g2f2 e2d2|c2ec B2dB|c2A2 A2df|
g2gf g2Bd|g2f2 e2d2|c2ec B2dB|A2F2 G4:|

More information about sequence diagrams syntax here.
More information about flow charts syntax here.
More information about graphviz syntax here
More information about mermaid syntax here
More information about abc syntax here

Alert Area

:::success
Yes :tada:
:::

:::info
This is a message :mega:
:::

:::warning
Watch out :zap:
:::

:::danger
Oh No! :fire:
:::

Typography

Headers

# h1 Heading
## h2 Heading
### h3 Heading
#### h4 Heading
##### h5 Heading
###### h6 Heading

Horizontal Rules

---

---

---

Typographic Replacements

Enable typographer option to see result.

(c) (C) (r) (R) (tm) (TM) (p) (P) +-

test.. test... test..... test?..... test!....

!!!!!! ???? ,,

Remarkable -- awesome

"Smartypants, double quotes"

'Smartypants, single quotes'

Emphasis

This is bold text

This is bold text

This is italic text

This is italic text

Deleted text

lu_lala

Superscript: 19^th

Subscript: H₂O

Inserted text

Marked text

Blockquotes

Blockquotes can also be nested...

...by using additional greater-than signs right next to each other...

...or with spaces between arrows.

Lists

Unordered

• Create a list by starting a line with +, -, or *
• Sub-lists are made by indenting 2 spaces:
  • Marker character change forces new list start:
    • Ac tristique libero volutpat at
    • Facilisis in pretium nisl aliquet
    • Nulla volutpat aliquam velit
• Very easy!

Ordered

1. Lorem ipsum dolor sit amet
2. Consectetur adipiscing elit
3. Integer molestie lorem at massa

1. You can use sequential numbers...
2. ...or keep all the numbers as 1.
3. feafw
4. 332
5. 242
6. 2552
7. e2

Start numbering with offset:

1. foo
2. bar

Code

Inline code

Indented code

// Some comments
line 1 of code
line 2 of code
line 3 of code

Block code "fences"

Sample text here...

Syntax highlighting

var foo = function (bar) {
  return bar++;
};

console.log(foo(5));

Tables

Option	Description
data	path to data files to supply the data that will be passed into templates.
engine	engine to be used for processing templates. Handlebars is the default.
ext	extension to be used for dest files.

Right aligned columns

Option	Description
data	path to data files to supply the data that will be passed into templates.
engine	engine to be used for processing templates. Handlebars is the default.
ext	extension to be used for dest files.

Left aligned columns

Option	Description
data	path to data files to supply the data that will be passed into templates.
engine	engine to be used for processing templates. Handlebars is the default.
ext	extension to be used for dest files.

Center aligned columns

Option	Description
data	path to data files to supply the data that will be passed into templates.
engine	engine to be used for processing templates. Handlebars is the default.
ext	extension to be used for dest files.

Links

link text
link with title
Autoconverted link https://github.com/nodeca/pica

Images

Like links, Images also have a footnote style syntax

With a reference later in the document defining the URL location:

Show the image with given size

Footnotes

Footnote 1 link^[1].
Footnote 2 link^[2].
Inline footnote^[3] definition.
Duplicated footnote reference^[2].

Definition Lists

Term 1

Definition 1
with lazy continuation.

Term 2 with inline markup

Definition 2

  { some code, part of Definition 2 }

Third paragraph of definition 2.

Compact style:

Term 1 Definition 1 Term 2 Definition 2a Definition 2b

Abbreviations

This is an HTML abbreviation example.
It converts "HTML", but keeps intact partial entries like "xxxHTMLyyy" and so on.

---

1. Footnote can have markup
   and multiple paragraphs. ↩

2. Footnote text. ↩ ↩

3. Text of inline footnote ↩