A short guide to Leekboard

What is Leekboard?

Leekboard is an online synthesizing software that uses the advanced web audio API to play and combine different sounds to a song. Just throw in your kicks, snares, vocals and other samples and create a song in no time.

How do I start?

First of all, you need to register a few keys using the button in the top left corner:

A popup will appear. Now, just press any key on your keyboard to register it for playing. It will appear in the top left corner, you can just drag it aroung on the screen. If you have found a position for the button, press Save button layout to save its position. However, nothing will happen yet when you press this key.

When you have registered a few keys, you need to set a sound for every one of them. Click on one of the buttons you have created and a popup will appear. It contains a list of settings:

After you have set your sound, you can close the popup by clicking somewhere next to it in the gray area. Wait for the sound to load(until the button turns from red to gray) and press the corresponding key on your keyboard to play the sound.


Like mentioned before, sounds can have different modes:


A metronome plays a beat at a given tempo. It is always given preference over repeating and song sounds when a sound is synced. In addition, a major beat can be specified to achieve specific rhythms. If Allow sync only on major beats is turned on, the sounds will only sync to these major beats. The metronome is not included if a song is recorded.

Sequence settings

Just above the settings menu, the sequence editor can be accessed. Here, sequences of key events (key pressed - key released) can be specified. To do that, first create a sequence using the New-button. Sequences can also be cloned and deleted, but be careful as they can not be recovered once deleted.

Once you have created a sequence, events can be added to it. There are two ways to do this:

If you accidentally added an event, it can be removed using the corresponding button or the delete key on your keyboard.

After you have added some events, they can be changed by dragging or resizing. In addition, they can be selected in order to either change multiple events at once (press shift while selecting) or to accurately change the start and end of a single event by entering numbers. When you press escape, the process of moving/resizing or the selection is cancelled. In addition, the a-key can be pressed in order to either select or deselect all events.

When moving or resizing events, the can be configured to snap either to time intervals (specified in seconds) or to other events.


In the bottom right corner, you can open the settings:

Exporting/loading layout

If you have a button layout you like to use and want to work on another computer, you can press Export layout to get a copyable string for your layout. You can then press Load layout on any other (or the same) browser window and paste your string there.


When you have gotten used to playing on leekboard for a bit, you may want to record your own song. This is done in a quite simple process:

  1. Press the record button on top of your screen:
  2. Play your song
  3. Press the record button again
  4. Wait for your song to process

Now you can save your song and share it with everyone else.