Can someone explain to me what turbo mode is I don't quite understand. Thank you!

It makes the project run faster.

There's a section in the Scratch Wiki that says the following:

In turbo speed, all scripts run at extreme speed. This is very useful for speeding up mathematical projects, however makes features such as graphic effects and clicking on sprites lag quite a bit.

In the Flash Player turbo speed is instead named “Turbo Mode”, which is accessed by shift-clicking the Green Flag. This is much faster than the Squeak (offline) turbo speed, making projects up to 50 times faster. Turbo speed between the online and offline editors differs greatly.

Saying “it makes scripts faster” (or even, as the wiki says, “run at extreme speed”) is a little misleading…

All blocks in a script always run at full speed, regardless of turbo. The difference is to do with the way it schedules loops in scripts (e.g. “repeat until”, “forever”, etc.)


When NOT using turbo, the Scratch Player restricts the loops to run at the same speed as the Flash refresh rate, which is 30 frames per second – but only if there was a block somewhere which potentially changed something on-screen, such as “go to”, etc. In other words, a loop containing a “go to” block will only run ~30 times in one second.

When turbo is enabled, Scratch no longer throttles loops in this way, so it will run as many times through the loops as it can before it does the next screen refresh.

Note that if none of the currently running loops execute a block that (potentially) changes something on-screen, then all those loops will run at ‘turbo-speed’ anyway.


For more technical details, and examples, see here: https://scratch.mit.edu/discuss/post/1526526/

to turn on turbo mode press shift and click the green flag

@TheLogFather Thank you so much that is very helpful information. I'm somewhat new to scratch and was wondering what that was for a long time.