Does Steam Cloud sync saves between different players?

No. Steam Cloud is per account. It syncs your own saves between your own devices, so the same game picks up where you left off on a different PC or on Steam Deck. It never copies a save from your account to a friend's account, even when you are playing the same co-op world together.

Does Steam Family Sharing share save files?

No. Sharing a library lets someone else play your games, but each Steam account keeps its own saves and its own Steam Cloud space. The one thing to watch is two Steam accounts using the same Windows user account on one PC, because many games write saves to a Windows user folder and the two accounts then end up writing to the same files.

Why does my co-op progress disappear when a different friend hosts?

Because in host-based co-op the world only exists on the host's machine. Steam Cloud backs up each player's own copy, so when a different person hosts they load their own older copy of the world rather than the one you all played on last night.

What is a Steam Cloud conflict?

It is the dialog Steam shows when the copy in the cloud and the copy on the machine have both changed since the last sync, usually after playing offline. Steam cannot tell which one you want, so it asks you to pick, and choosing the wrong one overwrites the newer save.

How do you actually share a co-op save with friends?

Copy the save from the host's machine to the next host's machine, into the same folder and with the same structure, while the game is closed. Doing that by hand after every session is what tools like SaveSync automate.

Does Steam Cloud Share Saves Between Players?

This one catches out a lot of groups, usually after losing an evening’s progress: Steam Cloud does not share saves with your friends.

It is a backup and device-sync feature, not a multiplayer one. Worth knowing exactly where the line falls before you rely on it.

What Steam Cloud Actually Does

Steam Cloud keeps a copy of your save files, attached to your Steam account.

Play on your desktop, then open the same game on a laptop or Steam Deck, and Steam pulls that copy down so you continue where you stopped. That is the whole feature, and it is genuinely good at it.

The scope is the important bit: one account, that account’s devices, that account’s saves.

What Steam Cloud Does Not Do

It does not copy saves between accounts. Your friend’s Steam Cloud holds their files. Yours holds yours. Playing the same co-op world together all evening does not merge them - and there is no setting that changes this, because it is not a limitation, it is the design.

It does not make a co-op world shared. In host-based co-op the world lives on whoever hosted. Everyone else is a visitor: they see the world over the network, but nothing of it lands on their disk. So Steam Cloud is dutifully backing up, for each of your friends, a save that does not contain last night’s session at all.

It does not cover every game, or every file. Support is per title, and some games sync only settings and profiles while leaving worlds out. A few use Steam Auto-Cloud, which matches files by path, so a save written somewhere unexpected is silently skipped.

What About Steam Families?

Sharing a library lets someone else play your games. It does not share progress - each account keeps its own saves and its own cloud space.

There is one practical trap. Many games write saves into a Windows user folder rather than anywhere Steam-account-specific. If two people share one Windows account on one PC and just switch Steam logins, both are writing to the same files, and the cloud sync prompt starts offering to overwrite one person’s progress with the other’s. Separate Windows user accounts avoid this entirely.

The Conflict Dialog Nobody Reads Properly

Sooner or later Steam shows a sync conflict: the cloud copy and the local copy have both changed since they last matched, usually because someone played while offline.

Steam has no way to know which one you want, so it asks. Pick wrong and the newer save is gone. If you see this dialog and are not certain, stop and check the timestamps rather than clicking through - there is no undo afterwards.

Manually, the shape is always the same:

Close the game on the host’s machine so nothing is mid-write.
Find the save folder for that game.
Copy it to the next host’s machine, into the same folder, with the same structure and names.
They launch the game and host from it.

It works. The problem is that it has to happen after every single session, and the moment two people host from copies made at different times, somebody’s evening is overwritten. That is the failure mode Steam Cloud cannot help with, because from its point of view nothing went wrong - it faithfully synced an out-of-date file.

Where SaveSync Fits

SaveSync does the part Steam Cloud deliberately does not: it syncs a co-op save between players, peer to peer, so every PC in your group has the current world and anyone can host tonight.

It is not a replacement for Steam Cloud - they solve different problems, and running both is fine. Steam Cloud protects you from losing your own files. SaveSync stops the group from being locked out because one person is busy.

The One-Line Version

Steam Cloud syncs your saves across your devices. It has never synced saves between people, and it was never meant to.

If your group keeps waiting on one host, that is the actual problem to solve: see how to play co-op when the host is offline, how to share game saves with friends, or how to back up co-op game saves.