Firefox Privacy Notice by Mozilla

Firefox Privacy Notice

Effective June 2, 2025

At Mozilla, we believe that privacy is fundamental to a healthy internet

That’s why we build Firefox, and all our products, to give you greater control over the information you share online and the information you share with us. In this Privacy Notice, we explain what data we process, how we process it, and for what purposes. Then, we explain how you can exercise choices about how we process your information.

How is your data used?

To provide you with the Firefox browser

Mozilla collects certain data, like technical and settings data, to provide the core functionality of the Firefox browser and associated services, distinguish your device from others, remember and respect your settings, and provide you with default features such as New Tab, PDF editing, password manager and Total Cookie Protection. You can further customize your Firefox experience by adjusting your controls, buttons, and toolbars and adding features with add-ons.

Some Firefox features, like automated translation for web pages and “alt-text” suggestions when you upload images in your PDFs, are powered by artificial intelligence (AI) based on small language models downloaded to your device. These operate locally — web page content, PDFs, images and tab URLs stay on your device and are not sent to Mozilla’s servers or used for training purposes without your explicit consent. Note that other Firefox features may integrate third-party AI models, as further detailed in this Notice.

More details, including how to adjust your data settings

You can read more detailed information about the information we collect for Desktop, Android or iOS. You can update your data collection settings for Desktop and Mobile at any time.

To adapt Firefox to your needs

Firefox processes a variety of personal data in a way that does not leave your device, such as browsing history, web form data, temporary internet files, and cookies. This means the data stays on your device and is not sent to Mozilla’s servers unless it says otherwise in this Notice. If you choose to allow it, your precise location may also be processed for location-related functionality for websites like Google Maps; this data is only accessed from your device by the website(s) you choose to enable it for — it is not sent to Mozilla's servers.

More details, including how to adjust your data settings

Data processed on your device remains in your control. You can manage your browsing data and your local storage settings, or update your location permissions at any time.

To provide and improve search functionality

When you perform a search in Firefox, your search query, device data and location data will be processed by your default search engine (according to their applicable Privacy Notice) to provide your search results and search suggestions. Mozilla generally receives royalties when you use one of the default or optional search options in the Firefox web browser.

Firefox also shows its own search suggestions based on information stored on your local device (including recent search terms, open tabs, and previously visited URLs). These suggestions may include sponsored suggestions from Mozilla’s partners, relevant content from common internet resources (such as Wikipedia), or relevant URLs that are popular in your country. Mozilla processes certain technical and interaction data, such as how many searches you perform, how many sponsored suggestions you see and whether you interact with them. Mozilla's partners receive de-identified information about interactions with the suggestions they've served. You can enable or disable Search suggestions at any time.

Depending on your location, Mozilla derives the high level category (e.g., travel, shopping) of your search from keywords in that query, in order to understand the types and number of searches being made. We utilize privacy preserving technologies such that Mozilla only learns that someone, somewhere, performed a search relating to a particular category, without knowing who. Learn more about how we categorize searches, including how to opt out.

Mozilla may also receive location-related keywords from your search (such as when you search for “Boston”) and share this with our partners to provide recommended and sponsored content. Where this occurs, Mozilla cannot associate the keyword search with an individual user once the search suggestion has been served and partners are never able to associate search suggestions with an individual user. You can remove this functionality at any time by turning off Sponsored Suggestions — more information on how to do this is available in the relevant Firefox Support page.

You may be able to opt into an enhanced search experience, which will result in Mozilla processing additional personal data, including your technical data, location and search data. Some of that information may be shared with our partners on a de-identified and/or aggregated basis. See our “Data and Firefox Suggest” blog post for more details.

More details, including how to adjust your data settings

You can update your Search settings and Search suggestion features, at any time, and learn more about how we categorize searches.

To serve relevant content and advertising on Firefox New Tab

We use technical data, language preference, and location to serve content and advertising on the Firefox New Tab page (referred to as home page on mobile) in the correct format (i.e. for mobile vs desktop), language, and relevant location. Mozilla collects technical and interaction data, such as the position, size, views and clicks on New Tab content or ads, to understand how people are interacting with our content and to personalize future content, including sponsored content. This data may be shared with our advertising partners on a de-identified or aggregated basis.

In some instances, when ads are enabled on New Tab, additional browsing data may also be processed locally on your device to measure the effectiveness of those ads; such data will only be shared with Mozilla and/or our advertising partners via our privacy-preserving technologies on an aggregated and/or de-identified basis.

When a user visits a third-party website by clicking an advertisement or link in Firefox, that site may use cookies and other web APIs available to any website to collect data subject to that website’s privacy and/or cookie notices.

More details, including how to adjust your data settings

You can read more information about how to manage your New Tab page including your data settings for Desktop, Android or iOS. You can opt out of having your data processed for personalization or advertising purposes by turning off data on Desktop and Mobile at any time.

To provide Mozilla accounts

If you sign up for a Mozilla account, we process additional information alongside the data set out in this Notice, such as account details, contact information and sync data, in accordance with the Mozilla Accounts Privacy Notice.

To provide AI chatbots

You have the option to use a third-party AI chatbot of your choice to help you with things like summarizing what you’re reading, writing and brainstorming ideas, subject to that provider’s terms of use and privacy notice.

If you choose to enable a chatbot in the sidebar and/or through a shortcut, Mozilla does not have access to your conversations or the underlying content you input into the selected chatbot. We do collect technical and interaction data on how this feature is used to help improve Firefox, such as how often each third-party chatbot provider is chosen, how often suggested prompts are used, and the length of selected text.

More details, including how to adjust your data settings

You can read more about how to manage or remove AI chatbots in Firefox.

To provide Review Checker, including serving sponsored content

Review Checker is a Firefox feature that helps you determine whether reviews are reliable when you shop online with sites like Amazon.com, BestBuy.com and Walmart.com. If you opt in to using Review Checker, Mozilla will process information about the website and the product identifier of the products you view using our privacy preserving technology called OHTTP. OHTTP combines encryption and a third party intermediary server, helping prevent Mozilla from linking you or your device to the products you have viewed. We also collect technical and interaction data on how this feature is used to help improve Firefox.

By opting in to using Review Checker you also agree to be shown product recommendations and sponsored content. If you do not want to receive product recommendations and sponsored content, you can opt out of this feature under Review Checker settings at any time.

More details, including how to adjust your data settings

You can read more information about How to use Firefox Review Checker and how we implement privacy preserving tech such as OHTTP.

To provide and enable add-ons (addons.mozilla.org)

You can install add-ons from addons.mozilla.org (“AMO”) or from the Firefox Add-ons Manager, which is accessible from the Firefox menu button in the toolbar. We process your search queries in the Add-ons Manager to be able to provide you with suggested add-ons. If you choose to install any add-ons, Firefox will process technical, location and settings data, and periodically connect with Mozilla’s servers to install and apply the correct updates to your add-ons. We also collect technical and interaction data on usage of add-ons, to help improve Firefox.

When you visit the AMO website, Mozilla collects technical and interaction data about your usage of the site in accordance with our Mozilla Websites, Communications and Cookies notice.

More details, including how to adjust your data settings

Learn how to remove or enable add-ons. You can also review the Privacy Notice for the add-ons website.

To maintain and improve features, performance and stability

Mozilla runs studies within Firefox and makes certain experimental features available through Firefox Labs to test different features and ideas before they’re made available to all Firefox users or become part of the core Firefox offering — this allows us to make more informed decisions about what our users want and need. This research uses technical, system performance, location, settings and interaction data.

We also need to process data to keep Firefox operational, improve features and performance, and identify, troubleshoot and diagnose issues. For this we use technical, location and settings data, as well as interaction and system performance data (such as number of tabs open, memory usage or the outcome of automated processes like updates). In the rare situations where the information needed also includes limited browsing data (e.g., Top Level Domain annotations for page-load performance monitoring), it will be transmitted using OHTTP; this helps prevent Mozilla from linking you or your device to the data collected for this purpose.

On Desktop and Android, if Firefox encounters an unexpected issue, the Mozilla Crash Reporter will also ask if you wish to send us additional information, which may include sites that were open at the time of the crash and other browsing data. On Desktop and Android if you opt in to sending us crash reports automatically, we collect this information without prompting you each time; on iOS, crash reports contain less information and are sent automatically to us by default. You can change your settings at any time.

More information, including how to adjust your data settings

You can learn more about the studies you’re enrolled in and opt out of all (or a specific) studies at any time, and opt into experimental features through Firefox Labs. You can also learn more about the technical and interaction data we process, including how to turn it off.

To improve security

Because maintaining the latest version of Firefox helps keep you safe against vulnerabilities, desktop versions of Firefox regularly connect to Mozilla’s servers (or another service that you used to install Firefox) to check for software updates; updates for Android and iOS versions of Firefox are managed by Google’s Play Store and Apple’s App Store, respectively.

We also process technical data and settings data to protect against malicious add-ons. In addition to these standard processes, we use Google’s Safe Browsing Service to protect you from malicious downloads and phishing attacks, and validate web page and technical data with Certificate Authorities. As part of our work to improve privacy and security for all internet users, we collect technical data via OHTTP, to better understand, prevent and defend against fingerprinting.

For some Firefox users, Firefox routes DNS requests to a resolver service that has agreed to Mozilla’s strict privacy standards for resolvers. This provides added protection from privacy leaks to local networks and also from certain DNS security attacks. System logs of your DNS requests are deleted from the service within 24 hours and are only used for the purpose of DNS resolution. Learn more about DNS over HTTPS.

More details, including how to adjust your data settings

You can learn more about the upgrades and add-ons blocklist, Google’s Safe Browsing Service and OHTTP, or turn off technical and interaction data.

To understand usage of Firefox

We process data to better understand how you engage with our services, such as how much you use Firefox, your language preference, how often you use our search tools or interact with search suggestions, how fast pages load for you and how many ads or CAPTCHAs you see. This allows us to measure how people access and use our services, which helps improve our business and the functionality of Firefox.

More details, including how to adjust your data settings

You can update your data collection settings for Desktop and Mobile at any time (note that deselecting “Allow Firefox to send technical and interaction data to Mozilla” will not impact the Daily Usage Ping). This Daily Usage Ping solely provides us with de-identified information that a user is using Firefox and is not tied to any other data about you and can be opted out in the settings.

To market our services

When you allow us to do so, Firefox sends Mozilla data about the website domain or specific advertising campaign (if any) that referred you to our download page to help us understand and improve our marketing efforts. Firefox also shares information with our marketing partners to measure and improve these campaigns; what information is specifically shared varies (depending on how you discovered Firefox and your operating system) but generally includes how you were referred to our download page and whether you actively use Firefox. Where Firefox is pre-installed on your device, technical and interaction data (your device type and whether Firefox is used) will be sent to our marketing partners, and shared with Mozilla.

More details, including how to adjust your data settings

Learn more about what Campaign Measurement data is collected and shared, and how to opt out. Note: Firefox does not share information like your browsing history, search queries, or saved passwords with marketing technology partners. Mozilla only collects the data necessary to measure and improve our marketing campaigns.

To pseudonymize, de-identify, aggregate or anonymize data

As part of the activities outlined above, such as understanding usage of Firefox and measuring our marketing, we may create pseudonymous, de-identified, aggregated or anonymized data. We use technology that is appropriate to the circumstances, including identifier removal, OHTTP, or DAP — these help prevent data from being linked to you. In some cases, we may share or publish aggregated and anonymized data to facilitate research or as part of the lawful business purposes outlined above (such as sharing aggregated insights with advertising partners).

To communicate with you

Depending on your settings (and whether or not you have a Mozilla account), we may communicate with you via in-product messaging, send you communications (including marketing-related communications), or ask you to participate in research / surveys, or respond to customer support communications. You may also reach out to us directly, such as to report a broken site within Firefox. When you send us personal data via these methods, we will use the information only for the purpose you provided it. We also process interaction data related to these communications to better understand who has received our service-related announcements (such as new features, updates or security alerts).

To comply with applicable laws, and identify and prevent harmful, unauthorized or illegal activity

We may also be required to process your personal data to comply with applicable laws and protection purposes, such as:

Responding to lawful requests and complying with legal processes, such as responding to subpoenas, investigations, or requests from government authorities. Mozilla requires a valid Legal Process to compel the disclosure of specific user data to a government.

Responding to requests to exercise privacy rights, such as your right to access or delete your personal data.

Identifying, investigating and addressing potential fraudulent activities, or other harmful activities such as illegal activities, cyberattacks or intellectual property infringement (including filing or defending legal claims).

Performing internal compliance and security activities, such as audits and enterprise security management.

How is your data shared?

To provide our services as described above, we may disclose personal data to:

How long is your data kept?

We only retain your personal data for as long as necessary to fulfill the purposes outlined in this Privacy Notice. In general, we do not retain personal data for more than 25 months, but actual retention periods may vary depending on the type of data and the purpose(s) for which it was collected (for example, we retain your “first seen” date for the period of your use of Firefox, so we know how long you’ve been a Firefox user). Specific retention periods may also depend on the sensitivity of the data, the context of its collection, your settings and preferences, and our legal or contractual obligations to retain or delete your data, such as for fraud prevention, regulatory compliance, or service continuity. Once the retention period expires we securely delete your data, unless otherwise required by law.

Our services also use encrypted backup storage as another layer of protection to help recover from potential disasters; data in these environments is put beyond use and only processed for business continuity purposes. We may also retain data for extended periods of time on a de-identified or aggregated basis.

Your rights and choices

Your rights

As a Firefox user, you have the right to:

Be informed about what data we process about you, why and who it’s shared with (that’s this Notice!)

Request a copy of the data we have about you

Request portability of your data

Request correction of any data we hold about you that is inaccurate or incomplete

Have personal data we hold about you deleted (in certain circumstances)

In some cases, restrict or object to how we use your personal data

Complain to your relevant data protection authority if you have concerns about how we’re handling your personal data. We’d prefer it if you contact us first (via [email protected]), but you can also reach out to your relevant EU data protection authority, or search for (and contact) your local data protection authority

To make any of the above requests regarding your personal data, please contact us (Mozilla Corporation) through our Data Subject Access Request Portal; we will never discriminate against anyone for exercising their privacy rights. If you have any other questions regarding personal data or our privacy practices, please contact us at [email protected].

If you’re in the UK or EEA, you can also contact our Data Protection Officer at [email protected], or by mail at:

Bird & Bird DPO Services SRL
Avenue Louise 235 b 1
1050 Brussels
Belgium

We respond to all requests we receive from individuals wishing to exercise their data protection rights in accordance with applicable data protection laws, and we may need to ask you for additional information to confirm your identity before we can proceed with your request.

Please note that, when you request deletion of your Firefox data, it will be deleted within 30 days of the request (with the exception of Interaction Data, which has a standard retention period of 90 days and is automatically deleted at the end of this period).

Your choices

You can update your data collection settings for Desktop and Mobile at any time.

Firefox also provides Global Privacy Control (GPC), which you can enable to automatically notify websites not to sell or share information about your browsing session on that website. GPC operates as a “Do Not Sell” mechanism in some US states such as California, Colorado and Connecticut. It may also be used to indicate an opt-out of targeted advertising or general request to limit the sale or sharing of your personal data in those jurisdictions, as well as in jurisdictions such as the EU, UK, Nevada, Utah and Virginia.

What happens with international data transfers?

Mozilla (and our servers) are based in the United States. Because we are a global company, in order to provide the services outlined in this Privacy Notice, the information we collect may be accessed from locations where our people are located and data may also be transferred to other jurisdictions as a result of sharing data with our partners. Where appropriate, we ensure we have appropriate mechanisms in place (such as standard contractual clauses approved by the European Commission and other relevant authorities) to protect your personal data. You can contact [email protected] for information on the safeguards implemented for international transfers, or for copies of the relevant standard contractual clauses.

Applicability (Firefox version) and changes

Applicability

This Privacy Notice is for the most recent general release version of Firefox distributed by Mozilla. If you obtain Firefox elsewhere, or are running an older version, your copy of Firefox may contain different privacy characteristics.

Mozilla’s pre-release versions of Firefox (which are distributed through channels such as Nightly, Beta, Developer Edition and TestFlight) are development platforms frequently updated with experimental features and studies. In addition to the data collection described in this Privacy Notice, these versions by default may send certain types of web activity and crash data to Mozilla (and in some cases to our partners).

Changes

We may need to change this policy and our notices, in which case the updates will be posted online and we will update the effective date of this notice. If the changes are substantive, we will also announce the update more prominently through Mozilla's usual channels for such announcements, such as blog posts and forums.

Types of data defined

Lawful basis

Location

Language preference

Settings data

Unique identifiers

Interaction data | Contract to provide you with the necessary functionality for Firefox to operate.Legitimate interest in providing additional functionality, accessibility services and a more personalized experience. | You can read more detailed information about the information we collect for Desktop, Android or iOS. You can update your data collection settings for Desktop and Mobile at any time. You can also learn more about translation and adding alt-text to images in PDFs. | | To adapt Firefox to your needs | - Any data type | Legitimate interest in making the data on your device work for you.Consent where you choose to allow websites (like Google Maps) with access to your precise location to enable location-related functionality. | Data processed on your device remains in your control. You can manage your local storage settings or clear your browsing history at any time. | | To provide and improve search functionality | * Technical data

Location

Language preference

Settings data

Unique identifiers

System performance data

Interaction data

Search data | Legitimate interest in providing and improving search functionality, as well as a more personalized search experience and sponsored results.Consent when you choose to opt into an enhanced search experience and share additional personal data. | You can update your Search settings and Search suggestion features, at any time, and learn more about how we categorize searches. | | To serve relevant content and advertising on Firefox New Tab | - Technical data

Location

Language preference

Settings data

Unique identifiers

System performance data

Interaction data

Search data | Legitimate interest in providing you content that you’re interested in and making sure that the ads you see are relevant (which supports our ability to provide our products and services). | You can read more information about how to manage your New Tab page including your data settings for Desktop, Android or iOS. You can opt out of having your data processed for personalization or advertising purposes by turning off data on Desktop and Mobile at any time. | | To provide Mozilla Accounts | | | See our Mozilla Accounts Privacy Notice | | To provide AI Chatbots | * Technical data

Location

Settings data

Unique identifiers

Interaction data | Consent, when you choose to enable an AI Chatbot. | You can read more about how to manage or remove AI chatbots in Firefox. | | To provide Review Checker, including serving sponsored content | - Technical data

Settings data

Unique identifiers

Interaction data

Browsing data | Consent, when you choose to enable Review Checker. | You can read more information about How to use Firefox Review Checker and how we implement privacy preserving tech such as OHTTP. | | To enable add-ons (addons.mozilla.org, “AMO”), including offering personalized suggestions | * Technical data

Location

Settings data

Unique identifiers

Interaction data

Search data | Legitimate interest in providing and understanding usage of the AMO infrastructure, including reviewing add-ons and blocking those known to cause security, stability or performance issues.Consent, when you choose to enable a specific Mozilla provided add-on. Data processed by each add-on is governed by their own Privacy Policy. | Learn how to remove or enable add-ons.You can also review the Privacy Notice for the add-ons website. | | To maintain and improve features, performance and stability | - Technical data

Location

Settings data

Unique identifiers

System performance data

Interaction data

Browsing data | Contract to ensure that Firefox remains operational.Legitimate interest in performing research and measures to improve features, performance and stability.Consent when you choose to send us crash reports, which may include browsing data. | You can learn more about the studies you’re enrolled in and opt out of all (or a specific) studies at any time, and opt into experimental features through Firefox Labs. | | To improve security | * Technical data

Location

Settings data

Unique identifiers

System performance data

Browsing data (for DNS over HTTPs only) | Compliance with law in securing personal data as required under applicable privacy and cybersecurity regulations.Legitimate interest in providing additional security measures for all our users and enhancing the overall security of the internet (such as our anti-fingerprinting work). | You can learn more about the upgrades and add-ons blocklist, Google’s Safe Browsing Service and OHTTP, or turn off technical and interaction data. | | To understand usage of Firefox | - Technical data

Location

Settings data

Unique identifiers

Interaction data

Content data

System performance data

Language preference | Legitimate interest in understanding how Firefox is used, enabling improvements and performing business functions such as usage reporting and forecasting.Consent, where required under applicable law (e.g. when non-essential cookies are used), or where users engage with surveys or voluntarily submit other information. | You can update your data collection settings for Desktop and Mobile at any time (note that deselecting “Allow Firefox to send technical and interaction data to Mozilla” will not impact the Daily Usage Ping). This Daily Usage Ping solely provides us with de-identified information that a user is using Firefox and is not tied to any other data about you and can be opted out in the settings. | | To market our services | * Technical data

Location

Language preference

Settings data

Unique identifiers

Interaction data

Browsing data

System performance data | Legitimate interest in promoting our products and services, including sending marketing communications and measuring and improving our marketing campaigns.Consent, where required under applicable law (e.g. jurisdictions which require consent to receive marketing communications). | Learn more about what Campaign Measurement data is collected and shared, and how to opt out. Note: Firefox does not share information like your browsing history, search queries, or saved passwords with marketing technology partners. Mozilla only collects the data necessary to measure and improve our marketing campaigns. | | To pseudonymize, de-identify, aggregate or anonymize data | - All data types | Legitimate interest in taking privacy-enhancing measures prior to performing analytics or sharing data with partners. | | | To communicate with you | * Unique identifiers

Interaction data

Contact data

Content data

Language preference | Legitimate interest in letting you know about improvements or changes to our products or services, as well as reviewing and responding to questions or other requests. | | | To comply with applicable laws, and identify and prevent harmful, unauthorized or illegal activity | - All data types | Compliance with law in responding to data subject rights requests, responding to law enforcement requests, managing and protecting our (and our users) rights, property and/or safety.Legitimate interest, where compliance is not appropriate, in supporting legal or regulatory processes or requests, preventing fraud and managing and protecting our (and our users’) rights, property and/or safety. | Learn more about how we respond to lawful requests. |

Privacy policies for search providers

Google

Microsoft (Bing)

DuckDuckGo

Amazon.com

eBay.com

Wikipedia