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The PreferenceObject interface of the User Preferences API provides attributes and methods for reading and overriding user preferences.
Use the document's PreferenceManager (accessed via Navigator.preferences) to get access to the PreferenceObject objects representing each available preference.
The PreferenceManager interface inherits from EventTarget.
EventTarget PreferenceObjectThe override value if set, null otherwise.
PreferenceObject.value Read onlyThe override value if set, the UA default otherwise.
PreferenceObject.validValues Read onlyThe valid values for the override.
Resets any previously set override to null and fires the change event.
PreferenceObject.requestOverride()Requests an override of the preference and fires the change event on success.
Fired when the override is set or reset.
| Media Queries Level 5 # preference-object-interface |
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This page was last modified on May 7, 2026 by MDN contributors.
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