Rebuild the Launch Services Database with lsregister

Fix wrong default apps and duplicated 'Open With' entries by resetting macOS's application registry.

macOSlsregistertroubleshootingdefault-appsMedium risk

Run the lsregister binary with `-kill -r -domain local -domain system -domain user` to rebuild the Launch Services database.

01Command

Command

$ /System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -kill -r -domain local -domain system -domain user

02What it does

Launch Services maps file types to apps; when apps are moved or deleted without emptying the Trash, stale entries cause wrong defaults and ghost 'Open With' rows. lsregister -kill empties the database and -r rescans the specified domains (user, local, system) to rebuild it from the app bundles actually present. Restart the Dock or log out afterwards so open applications refresh their caches.

03Risk

RiskMedium risk

!Warning: All per-user default-application choices are reset — Firefox instead of Safari for HTML must be set again.

04Undo

✓No undo needed — this command does not change persistent state.

05Sources

LSRegister Command: Reset the Launch Services database in macOS
SS64 · technical · 2026-09-17
Evidence: Documents lsregister -kill -r -domain options for rebuilding the Launch Services registration database.
Bundle Types
Apple Developer · vendor-doc · 2026-09-17
Evidence: Apple documents app bundles and the document-type declarations Launch Services indexes.

Last verified: 2026-09-17 · Category: System & Settings

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