From Test-Scratch-Wiki

The Green Flag is clicked in this location.

The Green Flag is a programming feature that, when clicked, will start all scripts in that project that are hatted with the When Green Flag Clicked block. More simply, this block starts the project. When ⇧ Shift clicking the green flag, Turbo Mode will be activated.

In Scratch 2.0, Ctrl clicking would mute the project so that the project could not produce any sound ( click on a Mac). In the Scratch 1.4 offline editor, pressing the ↵ Enter key on a keyboard would also start all green flag scripts, when not prompted for input by the Ask () and wait block.


when gf clicked
The When Green Flag Clicked block has the green flag icon on it.

Without the flag, no Scratch projects would be able to run unless a key was pressed, a sprite was clicked, or a When () is Greater Than () hat block was triggered to activate the scripts. While creating a project is fully possible without the flag, it is not recommended and most users use the green flag.[citation needed]

Examples of projects which do not use the Green Flag block are:

  • Projects which just share an image
  • Slide shows where only key presses need to be used to move the images

Stop Sign

Main article: Stop Sign

The Stop Sign is the opposite of the flag; a project will end and fully stop all scripts when it is clicked or the Stop () block is used with the "all" option.


In Scratch 14Feb04, the first version of the flag was a purple go button. It was then changed to a green play button in the next version. After that, it was changed to a start button and stayed that way until Scratch 28May05 when it was turned into a green flag as it is today.

In Scratch 1.4 and the online Java player, by broadcasting scratch-startclicked the flag was activated, meaning a project can start if a sprite is clicked.

Conversely, a broadcast received block Hat Block with the broadcast scratch-startclicked activates when the green flag is pressed.

As it was never a planned feature, it does not function with Scratch 2.0, and the Scratch Team does not plan on adding it to these versions.[1]

Custom Block Insertion

Archive.png This article or section documents a feature not included in the current version of Scratch (3.0). It is only useful from a historical perspective.

In older versions of Scratch 2.0, the Green Flag icon could be placed into custom blocks and variables by adding the text "@greenFlag" to the custom block name.


A similar trick could be done with the stop sign by adding the text "@stop" to a custom block.

Requesting multiple clicks

Some users will request clicking the green flag a certain amount of times before playing. This improves the sync of the When Green Flag Clicked Blocks so that assets of the project will line up correctly.

See Also


  1. ar-topic:57153 Known Limitation 3
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