Have you heard of Google Takeout? It’s a service that allows you to export your data from selected Google services so that you can either have a backup or easily migrate to another platform. Google’s recent notice of shutting down Google Reader will lead to many people (including myself) exporting their data via Google Takeout so they can more easily switch to other feed readers.
So what do you get if you use Google Takeout to export your Google Reader data? Google’s Data Liberation Front blog explains that in their post titled Escaping From Google Reader. In short you get files for just about every activity (stars, likes, shares, etc.) but the most important file for migrating is the subscriptions file, which is provided in an xml format. You can upload that file to another service and save yourself the trouble of individually re-subscribing to each of your feeds.