Hi, I'm often shown games on my list as 'updated.' When I go into the game I do not see what has changed. I generally backup my games on an external drivee. Without re-downloading everything, is there any way I can see what has been updated? Whether it is a game patch, or extra content etc?

Some (most?) games have a changelog, which you can find though the "more" menu for said game in your library.

Although... exactly which changes it tells you about can differ between games.

Just go to your library, click a game with an update flag and open "more" dropdown menu. There should be a changelog.

But to be honest, I don't think I've seen update flags to show up because of extra content.

Thank you both for the info!

Some games have a changelog link showing, but it's a crapshoot as not all of them do. Even those that have a changelog may not get it updated right away or even at all. So there is no universal way to know with absolute certainty what has changed or whether it is relevant enough to re-download the game at this point in time. The best source of information that we actually have, is the "What did just update?" thread here in the forums. Subscribe to that thread and make a note somewhere of the current comment you've read up to in the thread. Scan it once a day/week or whatever from the last comment you read forward and you should get a good idea of what games changed and why, and sometimes the finer details including changelog information, some of which doesn't appear anywhere else. That's the most reliable source of update information we have on GOG ATM, thanks to mrkgnao and now also muntdefems.

https://www.gog.com/forum/general/the_what_did_just_update_thread