Steam Offline Mode has no time limit: an explanation

Contrary to popular belief, Steam Offline Mode has no time limit and is not tied to a specific computer, but it has a tendency to break often; this guide explains how to fix it so you can play your games forever.

Introduction

I constantly see people unknowingly spreading misinformation about how Steam Offline Mode operates and most of it dates back to 2004 when Steam was the annoying memory hog you had to install to play Half-Life 2 and the servers crashed and you couldn't decrypt the game files that were already on the DVD and couldn't play the game you paid money for. But things have changed since then. This post exists to explain how there is no time limit on Steam offline mode and Steam isn't going to prevent you from preserving your games forever, assuming you take steps to back up your installation (which you should do anyway for any digitally downloaded games.)

Things about Steam offline mode that aren't true

• "You need to reconnect every x days to keep using offline mode"/"It has a time limit of x days"
  
• "Your account is tied to the computer you logged in on"
  
• "You can't move your games to another computer"

Things about Steam offline mode that are true

• Games need to be up-to-date to be launched (but Steam doesn't actually check the game files, just the appmanifest)
  
• Family shared games are not accessible offline (unless, of course, you log into the account that owns them)
  
• Games with third-party DRM often won't work (blame the devs)
  
• Offline mode can randomly break due to bad coding on Valve's part (but this can be bypassed, see "Things you need to use offline mode" below)

Time limit

There is no practical time limit on Steam offline mode. You can prove this easily by exiting Steam, disconnecting from the internet, setting your system clock forward 10 years, and reopening Steam--if you saved your password, it'll offer to launch in offline mode, and everything will still work.

There is *technically* a time limit in the sense that Steam suffers from Y2K38[en.wikipedia.org]; after 19 January 2038 03:14:07 UTC, Steam will still open but games will crash on launch. This can, of course, be worked around by setting the clock back, and will probably be fixed before that time actually passes.

Game transfer

Steam detects whether a game is installed based on the presence of an "appmanifest_[appid].acf" file in the library folder. You can find a game's appid in the Updates tab of its Properties window. You can move games between computers as long as you copy both the game folder and its appmanifest file. (of course, the account you're signed into needs to own the game)

System transfer

Steam installations are not computer-specific. You can copy the Steam install folder to another computer and it will still work offline as long as you make one registry key (or edit a text file on Linux/macOS). This is detailed below.

Things you need to use offline mode

• You need a copy of the client, obviously, and it needs to have appinfo.vdf and packageinfo.vdf caches in the appcache folder (which are auto-created when you go online.) You can "install" the client by just copying the install folder to another computer, because Steam doesn't actually care where it's installed (or even that the installer ran at all.)
  
• The client must not think it needs to check for updates. Sometimes when Steam crashes it tries to force an update check which will always fail due to lack of internet. To prevent the updater from ever running, create a file in the same folder as the steam executable named "steam.cfg" with the following contents:

  BootStrapperInhibitAll=enable

• The file Steam/config/config.vdf must include the Accounts block that maps usernames to SteamIDs.
  
• The file Steam/config/loginusers.vdf must contain an entry for your account with RememberPassword and AllowAutoLogin set to 1. (WantsOfflineMode should probably also be set to 1 for good measure to prevent the client from attempting to go online first.)
  
• The file Steam/userdata/[32-bit steamid]/config/localconfig.vdf must contain your account's parental settings (or the client will refuse to login) and at least one license (or the client will hang on "Connecting Steam account").
  
• The Windows registry (or registry.vdf file in ~/.steam/registry.vdf on Linux) must contain a key specifying which account to login as: REG_SZ (string) key "HKEY_CURRENT_USER\SOFTWARE\Valve\Steam\AutoLoginUser". It must be set to your account name (the one you enter on the login screen.)

That's it. Contrary to Valve's claims, you don't actually need to have checked the remember password box, you can just make the registry and loginusers changes manually and then disconnect from the internet.

"It broke how do I fix it"

If your Steam offline mode used to work and now you get an error saying you need to be connected to the internet to update, make a steam.cfg file as detailed above.

If your Steam offline mode used to work and now you get the login screen or a connection error with no option to launch offline, the problem is probably the loginusers.vdf file. Open it in a text editor (by default it's at C:\Program Files (x86)\Steam\config\loginusers.vdf), find your account in the list, and change the RememberPassword, AllowAutoLogin, and WantsOfflineMode values to "1".

tl;dr

Backup your Steam install folder, make one registry key, and you can play your games offline forever on any computer.

Dear Valve:

If Steam offline mode is, as you say, "designed to be indefinite": Please stop running forced update checks if the client crashes without internet. Please stop making the client refuse to launch if it runs an update check on an unsupported operating system version. And also, would it really be that hard to allow users to log in offline without having to have some specific random values set in loginusers.vdf or manually change a registry key? The reason everyone thinks Steam has a DRM time limit despite it not having one is because it has a tendency to randomly break offline in ways that appear identical to hitting a time limit. It would not be very difficult for you to fix this.