Preferences

This document describes preferences affecting the address bar and the search bars. Preferences that are generated and updated by code won’t be described here.

Search Bars

A search bar reads an address bar preference wherever it runs the same code. Which preferences apply depends on the results each bar shows. The toolbar search bar shows search suggestions, search history and a few built-in results such as the calculator. The New Tab search bar adds URL navigation, autofill and Firefox Suggest, and the smartbar shows most address bar results.

These preferences affect only the address bar:

• browser.urlbar.shortcuts.bookmarks, browser.urlbar.shortcuts.tabs and browser.urlbar.shortcuts.history

• browser.urlbar.showSearchTerms.enabled

• browser.urlbar.accessibility.tabToSearch.announceResults

• browser.urlbar.dnsResolveSingleWordsAfterSearch

• browser.urlbar.formatting.enabled

• browser.urlbar.searchTips.test.ignoreShowLimits

• browser.urlbar.sponsoredTopSites

Some search bars read a different preference, or ignore one:

• The toolbar search bar reads browser.search.openintab instead of browser.urlbar.openintab.

• The smartbar reads browser.urlbar.smartbar.maxResults and browser.urlbar.smartbar.showSearchSuggestionsFirst instead of browser.urlbar.maxRichResults and browser.urlbar.showSearchSuggestionsFirst.

• The toolbar and New Tab search bars ignore keyword.enabled and browser.urlbar.unifiedSearchButton.always, and show recent searches regardless of browser.urlbar.suggest.recentsearches.

User Exposed

These preferences are exposed through the Firefox UI.

browser.urlbar.shortcuts.bookmarks (boolean, default: true)

Whether to show the bookmark search shortcut button in the view. Can be controlled from Search Preferences.

browser.urlbar.shortcuts.tabs (boolean, default: true)

Whether to show the tabs search shortcut button in the view. Can be controlled from Search Preferences.

browser.urlbar.shortcuts.history (boolean, default: true)

Whether to show the history search shortcut button in the view. Can be controlled from Search Preferences.

browser.urlbar.showSearchSuggestionsFirst (boolean, default: true)

Whether to show search suggestions before general results. Can be controlled from Search Preferences.

browser.urlbar.showSearchTerms.enabled (boolean, default: true)

Whether to show the search term in the urlbar on a default search engine results page. Can be controlled from Search Preferences.

browser.urlbar.suggest.bookmark (boolean, default: true)

Whether results will include the user’s bookmarks. Can be controlled from Privacy Preferences.

browser.urlbar.suggest.history (boolean, default: true)

Whether results will include the user’s history. Can be controlled from Privacy Preferences.

browser.urlbar.suggest.openpage (boolean, default: true)

Whether results will include switch-to-tab results. Can be controlled from Privacy Preferences.

browser.urlbar.suggest.quicksuggest.all (boolean, default: false)

If browser.urlbar.quicksuggest.enabled is true, this controls whether results will include suggestions that are part of the Firefox Suggest brand. Otherwise they will not be included.

browser.urlbar.suggest.quicksuggest.sponsored (boolean, default: false)

If browser.urlbar.quicksuggest.enabled and browser.urlbar.suggest.quicksuggest.all are true, this controls whether results will include sponsored Firefox Suggest suggestions. Otherwise they will not be included.

browser.urlbar.suggest.searches (boolean, default: true)

Whether results will include search suggestions. Can be controlled from Search Preferences.

browser.urlbar.suggest.engines (boolean, default: true)

Whether results will include search engines (e.g. tab-to-search). Can be controlled from Privacy Preferences.

browser.urlbar.suggest.topsites (boolean, default: true)

Whether results will include top sites and the view will open on focus. Can be controlled from Privacy Preferences.

browser.search.suggest.enabled (boolean, default: true)

Whether search suggestions are enabled globally, including the separate search bar. Can be controlled from Search Preferences.

browser.search.suggest.enabled.private (boolean, default: false)

When search suggestions are enabled, controls whether they are provided in Private Browsing windows. Can be controlled from Search Preferences.

Hidden

These preferences are normally hidden, and should not be used unless you really know what you are doing.

browser.urlbar.accessibility.tabToSearch.announceResults (boolean: default: true)

Whether we announce to screen readers when tab-to-search results are inserted.

browser.urlbar.addons.featureGate (boolean, default: false)

Feature gate pref for add-on suggestions in the urlbar.

browser.urlbar.autoFill (boolean, default: true)

Autofill is the the feature that automatically completes domains and URLs that the user has visited as the user is typing them in the urlbar textbox.

browser.urlbar.autoFill.adaptiveHistory.enabled (boolean, default: false)

Whether adaptive history autofill feature is enabled.

browser.urlbar.autoFill.adaptiveHistory.useCountThreshold (float, default: 1.0)

Threshold for use count of input history that we handle as adaptive history autofill. If the use count is this value or more, it will be a candidate.

browser.urlbar.autoFill.adaptiveHistory.urlMinPicks (integer, default: 3)

Approximate number of times the user must have picked a URL with a path for a given input string before it can be adaptive history autofilled.

This is not an exact pick count. It is converted into a moz_inputhistory.use_count threshold, and use_count decays twice over: once per pick, as addToInputHistory applies a factor to the previous value, and again once per idle-daily, as PlacesFrecencyRecalculator decays every row by places.frecency.decayRate. Whether a URL clears the threshold therefore depends on how its picks were spread over time, not just how many there were. Raising this value always makes page autofill rarer, but the number of picks a given user needs depends on their cadence.

browser.urlbar.autoFill.adaptiveHistory.urlPicksAgeDays (integer, default: 14)

Days of idle decay assumed to have elapsed since the last pick when converting urlMinPicks into a use_count threshold.

The threshold is the use_count left behind by urlMinPicks picks made in one sitting and then aged this many days, which is a pessimistic estimate: a user who really did pick the URL that many times clears it even if their picks were spread out. Raising this lowers the threshold and so admits users who pick a URL less often; lowering it raises the threshold.

browser.urlbar.ctrlCanonizesURLs (boolean, default: true)

Whether using ctrl or command when hitting return/enter in the URL bar should add prefix ‘www.’ and suffix Services.locale.urlFixupSuffix to the user value prior to navigating.

browser.urlbar.decodeURLsOnCopy (boolean, default: false)

Whether copying the entire URL from the location bar will put a human readable (percent-decoded) URL on the clipboard.

browser.urlbar.delay (number, default: 50)

The amount of time (ms) to wait after the user has stopped typing before fetching certain results. Reducing this doesn’t make the Address Bar faster, it will instead make it access the disk more heavily, and potentially make it slower. Certain results, like the heuristic, always skip this timer anyway.

browser.urlbar.dnsResolveSingleWordsAfterSearch (number, default: 0)

Controls when to DNS resolve single word search strings, after they were searched for. If the string is resolved as a valid host, show a “Did you mean to go to ‘host’” prompt. Set to 0. 0: Never resolve, 1: Use heuristics, 2. Always resolve.

browser.urlbar.filter.javascript (boolean, default: true)

When true, javascript: URLs are not included in search results for safety reasons.

browser.urlbar.focusContentDocumentOnEsc (boolean, default: true)

Focus the content document when pressing the Escape key, if there’s no remaining typed history.

browser.urlbar.formatting.enabled (boolean, default: true)

Applies URL highlighting and other styling to the text in the urlbar input field. This should usually be enabled for security reasons.

browser.urlbar.maxCharsForSearchSuggestions (integer, default: 100)

As a user privacy measure, we don’t fetch results from remote services for searches that start by pasting a string longer than this. The pref name indicates search suggestions, but this is used for all remote results.

browser.urlbar.maxHistoricalSearchSuggestions (integer, default: 2)

The maximum number of form history results to include as search history.

browser.urlbar.maxRichResults (integer, default: 10)

The maximum number of results in the urlbar popup.

browser.urlbar.merino.clientVariants (string, default: “”)

Comma separated list of client variants to send to send to Merino. See Merino API docs for more details. This is intended to be used by experiments, not directly set by users.

browser.urlbar.merino.providers (string, default: “”)

Comma-separated list of providers to request from the Merino server. Merino will return suggestions only for these providers. See [Merino API docs] for more details.

browser.urlbar.openintab (boolean, default: false)

Whether address bar results should be opened in new tabs by default.

browser.urlbar.quicksuggest.enabled (boolean, default: false)

Whether the quick suggest feature is enabled, i.e., sponsored and recommended results related to the user’s search string. This pref can be overridden by the quickSuggestEnabled Nimbus variable. If false, neither sponsored nor non-sponsored quick suggest results will be shown. If true, then we look at the individual prefs browser.urlbar.suggest.quicksuggest.all and browser.urlbar.suggest.quicksuggest.sponsored.

browser.urlbar.quicksuggest.online.available (boolean, default: false)

Whether online Firefox Suggest is available to the user. This is only relevant when Suggest overall is enabled. When true, a checkbox will be shown in the settings UI allowing to the user to toggle online Suggest.

browser.urlbar.quicksuggest.online.enabled (boolean, default: true)

Whether Firefox Suggest retrieves online suggestions from Merino. This pref is only relevant when Suggest overall is enabled and online Suggest is available to the user; otherwise online suggestions are disabled. In addition, when the relevant Oblivious HTTP (OHTTP) Merino prefs are set, online suggestions will be fetched over OHTTP.

browser.urlbar.richSuggestions.tail (boolean, default: true)

If true, we show tail search suggestions when available.

browser.urlbar.searchTips.test.ignoreShowLimits (boolean, default: false)

Disables checks that prevent search tips being shown, thus showing them every time the newtab page or the default search engine homepage is opened. This is useful for testing purposes.

browser.urlbar.speculativeConnect.enabled (boolean, default: true)

Speculative connections allow to resolve domains preemptively when the user is likely to pick a result from the Address Bar. This allows for faster navigation.

browser.urlbar.sponsoredTopSites (boolean, default: false)

Whether top sites may include sponsored ones.

browser.urlbar.suggest.addons (boolean, default: true)

If browser.urlbar.addons.featureGate is true, this controls whether add-on suggestions are turned on. Otherwise they won’t be shown.

browser.urlbar.suggest.yelp (boolean, default: true)

If browser.urlbar.yelp.featureGate is true, this controls whether Yelp suggestions are turned on. Otherwise they won’t be shown.

browser.urlbar.switchTabs.adoptIntoActiveWindow (boolean, default: false)

When using switch to tabs, if set to true this will move the tab into the active window, instead of just switching to it.

browser.urlbar.trimURLs (boolean, default: true)

Clean-up URLs when showing them in the Address Bar.

keyword.enabled (boolean, default: true)

By default, when the search string is not recognized as a potential url, search for it with the default search engine. If set to false any string will be handled as a potential URL, even if it’s invalid.

browser.fixup.dns_first_for_single_words (boolean, default: false)

If true, any single word search string will be sent to the DNS server before deciding whether to search or visit it. This may add a delay to the urlbar.

Experimental

These preferences are experimental and not officially supported. They could be removed at any time.

browser.urlbar.suggest.calculator (boolean, default: false)

Whether results will include a calculator.

browser.urlbar.unitConversion.enabled (boolean, default: false)

Whether unit conversion is enabled.

browser.urlbar.unitConversion.suggestedIndex (integer, default: 1)

The index where we show unit conversion results.

browser.urlbar.keepPanelOpenDuringImeComposition (boolean, default: false)

Whether the results panel should be kept open during IME composition. The panel may overlap with the IME compositor panel.

browser.urlbar.restyleSearches (boolean, default: false)

When true, URLs in the user’s history that look like search result pages are restyled to look like search engine results instead of history results.