Share Godot Web Builds online!

Updated: March 24, 2025

Our goal with SIMMER was always to support multiple engines, it just took awhile! We will be supporting Godot Web uploads starting March 24, 2025.

This feature is in Alpha right now, and we always appreciate it if you reach out to support@simmer.io if you're having a problem. The fastest way to get a response would be to share you Godot web export on Google Drive or similar and then email us the link. You can also try our discord server if you have any questions.

TL;DR

In Godot, Project => Export
Add... Web (Runnable), and select Web Runnable.
"Export Project..." to a new empty folder.
Drag folder to https://simmer.io/upload

Details

So far we've tested Godot 4.3, and 3.5 with default settings so those are known working. Other versions will likely work too.

In this tutorial, we'll upload "Platformer 3D Demo" to SIMMER.

Open Godot and select Asset Library and search for "platformer 3d". Import the project.

Go to Project => Export

In the export window, click Add => Web.

This will add "Web (Runnable)" to your presets list. Select "Web (Runnable)", then click "Export Project" (not "Export PCK / Zip!").

Important: In the "Save a File" window, create a new folder such as "Web Export".

If you fail to do this, your web project will save a bunch of files in your project directory, and will make a mess. SIMMER will reject the upload because we don't want a bunch of your other project files. We only want the web export.

Double click that to enter it, and save the .html file with the default name. You can leave "debug" on or off depending on if you plan to troubleshoot.

For SIMMER, we recommend the Godot default settings. For reference, I'll include some screens of those settings at the end of this article.

Test your build locally (Recommended)

This section has some great info to add to your development tool chest, but if you want to skip ahead directly to the Upload section, I won't tell anybody.

Open CMD on Windows or Terminal on Mac. Check if you have python installed by typing "python --version" or "python3 --version". If you don't have it, you may need to install python.

In my case I have Python 3 at python3.

cd into your export directory. This might look slightly different on windows, and you may need quotes around the directory name if there are spaces in the path. Then type "python3 -m http.server 9494". This starts a server, serving the Web export at localhost:9494. You can try other random 4 digit port numbers if 9494 is in use.

If you have Python 2, the command is slightly different: python -m SimpleHTTPServer 9494.

In your browser, go to http://localhost:9494, and click your HTML file.

At this point your game should be running locally!

Hint 1: Your game will only be available on your local computer, not other computers on the network or internet. If you want to test on mobile, for instance, you can use a tool called ngrok which exposes localhost to the internet at a unique URL. It's fairly easy to set up, but I'm not going to cover it in detail here.

Hint 2: Issues with your game? Open Google Chrome Devtools! This will have a console that might print relevant info that can help you.

Note! If the game doesn't work on localhost, it definitely will not work on SIMMER! Usually if your game doesn't run locally, that's outside of the support that we're willing to provide. Sorry, I'm not a Godot expert! I know just enough to get by.

Upload to SIMMER

This part is really easy! Simply drag your "Web Export" folder onto https://simmer.io/upload. Remember that you want your Web Export folder and not your project folder!

Fill out the info on the upload page, and then click "continue". There will be a few other questions such as adding a game description.

SIMMER is smart enough to collect screenshots every 5 seconds or so when you're on this staging page. If you like the screenshots we've collected, you can use one of those, or upload a custom screenshot from your computer.

On the last page you'll add your description.

When you click "Finish", your game will be live on the web!

Hint: want even more, such as adding your own custom loading screen or serving your game from a custom domain? Try our premium product, SIMMERconnect!

Appendix: Godot Default Web Export Settings

For your reference, here are the Godot default settings that we've tested on SIMMER. You may be able to try other settings, but they're not guaranteed to work.

Sadly, SIMMER specifically doesn't support "Threading Support". There's a whole rabbit hole that I went down trying to get that to work, but because of the way that we embed games into the main website via an iFrame, we can't enable something called Cross-Origin Isolation, a web security rule. We also want to support embedding onto other websites, and we especially cannot guarantee Cross-Origin Isolation there.