In addition, the Workshop provides a way for developers to directly integrate user-created content into their games. Mods installed via the Steam Workshop will auto-update, so be careful about non-backward compatible changes as previous saves may become unplayable.Users can also browse workshop content created by other users, rate and comment on it, and subscribe to content that they want to be automatically updated. Maximum file size prevents large mods from using the Workshop.Modular mods that allow selecting modules at installation steps cannot be managed.The workshop has a few limitations, making it currently unsuitable for large mods: Manage button is always greyed out: activate Steam Cloud Synch' for Stellaris ( Steam -> Settings/(Preferences on mac) -> Cloud -> Enable cloud sync), it is required to upload mods.In order to update a mod, hit the 'Fetch Info' button before uploading the mod. MyMod.zip will contain a generated descriptor.mod which is identical to mymod.mod. Mod file when downloaded from Workshop (mymod.mod):

Once everything looks fine, make the mod public!.

Add a description, screenshots or videos, and edit change notes.

Copy the URL (ex: /sharedfiles/filedetails/?id=123456) and open in your favorite browser, as it's easier than using the Steam client integrated browser.

After upload is finished, mod page will open inside the Steam client.

In the menu, select the mod you wish to upload and click on 'Upload'.

Click on the 'Mod tools' button and select 'Upload mod' within the window that opens.

Launch the game launcher and go to the 'Mods' tab.

(Optional) Define an image banner and tags in.

Mod upload is managed from the game launcher:

In the Stellaris launcher, click the 'Mods' tab and check the box.

Find a mod on the Stellaris Steam Workshop.

Steam how to download workshop item