Disable Built-in PDF Viewer (PDF.js)

If this policy is enabled, PDF files are not viewed within Firefox.

If this policy is disabled or not configured, PDF files are viewed within Firefox.

Supported on: Firefox 60 or later, Firefox 60 ESR or later
Registry HiveHKEY_LOCAL_MACHINE or HKEY_CURRENT_USER
Registry PathSoftware\Policies\Mozilla\Firefox
Value NameDisableBuiltinPDFViewer
Value TypeREG_DWORD
Enabled Value1
Disabled Value0

firefox.admx

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