WoW Settings Transfer
Copy your keybinds and HUD layout from the World of Warcraft version you know to any other: Retail, WoW Forever, Classic, betas and PTRs, in any direction. Every file it replaces is backed up and can be restored with one click.
Start here: choose your World of Warcraft folder
Pick the folder that contains _retail_, _classic_ and so on. On a default install that's C:\Program Files (x86)\World of Warcraft. The browser will ask to let this page view and edit files there. Your keybinds and layouts never leave your computer: all the copying happens here in the browser, and none of it is uploaded anywhere. You only need this for keybinds and backups. The HUD layout tab works without it.
1Copy from and copy to
Some characters on the source account have their own keybinds. To bring one over, pick it and a destination character. Leave these blank to copy only the account-wide keybinds.
2Copy
Close both games first. WoW saves keybinds when you log out, so a running game will overwrite the copy.
This works between any two versions that have Edit Mode (Esc > Edit Mode), such as Retail, WoW Forever and the newer Classic versions. Versions without Edit Mode, like Classic Era, have no layout string to copy, but their keybinds still transfer on the Keybinds tab.
Shortcut: load your saved layouts
Choose your World of Warcraft folder at the top of the page and your saved layouts appear here, so you don't have to export and paste them by hand. WoW keeps them in WTF\Account\<account>\edit-mode-cache-account.txt. This only reads that file, it never changes it.
Close the game first, or pick its layouts again afterwards. WoW only writes this file when you log out, so anything you changed in this session won't be here yet.
1Your layout
In the game you're copying from, open Edit Mode (Esc > Edit Mode), select your layout, then use the layout menu > Export and paste it here. Or use the shortcut above.
2A layout from the game you're copying to
In the other game, export any layout (the default Modern preset is best) and paste it here. The converter uses it as a starting point, so the result always matches what that game version accepts.
3Convert
Afterwards, check anything attached to a bar or frame that looks different in the other version. The main action bar and XP bar are the usual ones. Nudge them in Edit Mode, then save.
Your backups
Each time this tool replaces a file, it saves the old one next to it first. Restoring a backup also saves the current file first, so you can undo a restore too. Close the game before restoring.