Where Does SumatraPDF Store Settings?
SumatraPDF settings file for installer, portable and shared setups, and the Store copies to avoid.
Last updated
SumatraPDF keeps everything in SumatraPDF-settings.txt: prefs, file states, favorites and session data, editable via Settings, Advanced Settings. Installed builds keep it in %LOCALAPPDATA%\SumatraPDF; portable builds keep it next to the exe.
Two edge cases matter. Installed outside Program Files with wrong permissions, Sumatra silently goes portable and writes beside the exe, which a reinstall to the default path fixes. And there is no official Store build: Store copies are fakes. Shared machines can force any folder with the -appdata flag.
Where SumatraPDF stores this, by platform
%LOCALAPPDATA%\SumatraPDF\SumatraPDF-settings.txt
Installer (per user) settings; thumbnail cache in the sumatrapdfcache sibling. Portable builds use <exe-dir>\SumatraPDF-settings.txt instead. Shared setups via SumatraPDF.exe -appdata <dir>. No official Microsoft Store build exists.
Frequently asked questions
My SumatraPDF settings keep resetting. Why?
It is probably running portable by accident: installed outside Program Files with bad ACLs, it writes next to the exe instead of LocalAppData. Full uninstall plus fresh install to the default path restores normal behavior.
How do I share SumatraPDF settings on a terminal server?
Launch with SumatraPDF.exe -appdata pointing at a shared writable folder both sessions use. The target dir must exist first; Sumatra does not expand env vars in that flag.
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