Publishing and storing hosted feature services in ArcGIS Online is one way to share data with an internet audience. Storing features in ArcGIS Online consumes credits, and the amount of consumed credits increases with the stored feature service size. In some instances, the hosted feature service size increases continuously, and consequently increases the amount of consumed credits, even though no updates are made to the feature service.
The feature service synchronization is enabled in the feature service settings. Enabling synchronization enables the option to create replicas on the service. Different versions are created and deleted in the background to allow offline editing. When synchronization is enabled, an additional table is created in the background to track the added, updated, and deleted records that increase the size of the hosted feature service.
Disable the feature service synchronization to clear the tracking table, and reduce the size of the feature service. To do this, go to the item details page of the feature service, click the Settings tab, scroll to the Feature Layer (hosted) section, and uncheck the Enable Sync option. Click Save to save the edited settings.