# When I play a script in the editor, where does the script traffic originate?
> Normally, Loadster plays scripts from the public cloud. Here's how to control where the script traffic originates from when you run scripts in the editor.
Source: https://loadster.com/faqs/where-does-script-traffic-originate/
Before launching a load test, it's smart to play your script in the editor with a single bot, just to make sure the
script is working correctly. This saves you the time and expense of running a load test with a broken script.
When you play a script in the editor, you'll see live feedback as the steps are executed, but the bot traffic isn't
actually coming from *your* web browser. Instead, it's coming from a Protocol Bot or a Browser Bot running on one
of our engines. The bot runs the script and streams back the results to your browser so you can see what's going on.
Normally these bots live on one of our shared engines in North America, Europe, Asia,
South America, and Australia. The location is chosen somewhat at random each time you play your script.
But if you need to run your scripts from a specific location, you can configure it.
## Specifying a cloud region for script playing
If you'd like to play from a specific cloud region, you can do so in Settings by choosing
that region from the **Script Player** dropdown. Loadster will always try to play from your preferred region.
Occasionally if the script players in that region are over-utilized or having trouble, we might
have to fall back on a different one, but this is rare.
## Specifying a self-hosted engine for script playing
If you have a [self-hosted Loadster Engine](https://loadster.com/manual/testing-with-loadster-engine/), you can play
scripts from it too. This is often necessary if you need to hit a site that's running on a private network, inaccessible
from our public cloud regions. Your self-hosted engines will appear in the same **Script Player** dropdown on the
Settings page, and you can choose them the same way.