The green flag is a push button placed on the IDE by create control bar, which behaves like the "start of the project". The icon has a green flag. (lightning bolt if turbo mode is enabled) The colour is always #00c800. When clicked, the flag triggers all when flag clicked blocks. In Scratch, it first stops all scripts and deletes all clones.

Clicking the green flag can be simulated programmatically with the broadcast blocks two ways:

• Click the green flag icon in the dropdown menu on the broadcast block. When done, the block should read something like .
• Create a new message and call it __shout__go__. The receive hat block with that message in it is also triggered when the actual green flag is clicked.

Note: When you click the green flag, the (message::control) reporter does not change. However, when __shout__go__ is broadcasted, the message reporter does change to __shout__go__. When the green flag icon is broadcasted, the message reporter also changes to __shout__go__.