Firefox automatically connects to us and our service providers to provide updates, security, Snippets, Firefox Health Report and other features.
Browser and add-ons updates
Browser Updates: Once per day, Firefox sends the following info to Mozilla when it checks for browser updates: your Firefox version information, language preference, operating system and version. You can turn off updates by following instructions here but it may leave you open to security vulnerabilities.
Add-ons Blocklist: Firefox contacts Mozilla once per day to check for add-on information to check for malicious add-ons. This includes, for example: browser version, OS and version, locale, total number of requests, time of last request, time of day, IP address, and the list of add-ons you have installed. You can turn off this functionality at any time by following these instructions, but it may leave you open to security vulnerabilities.
Firefox's default home page (<about:home>) loads small bits of information right below the search bar that we think will be useful to you. We call these "snippets". About once per day, Firefox connects to Mozilla and provides you with new snippets, if available. Mozilla aggregates how often snippets are clicked, snippet name, browser locale, and which version of Firefox you're using.
To help display relevant snippets, Firefox sends Mozilla a monthly request to look up your location at a country level using your IP address. We then send that country level information back to Firefox, where it's stored locally. Firefox will then choose snippets to show you based on the locally stored country information.
Firefox Health Report (FHR) is designed to provide you with insights about your browser's stability and performance and with support tips should you experience issues, such as high crash rates or slow startup times. Mozilla collects and aggregates your data with that of other Firefox users and sends it back to your browser so you can see how your Firefox performance changes over time. This data includes, for example: device hardware, operating system, Firefox version, add-ons (count and type), timing of browser events, rendering, session restores, length of session, how old a profile is, count of crashes, and count of pages. FHR does not send Mozilla URLs that you visit.
We use the data sent through FHR to provide users with FHR's functionality, such as helping you analyze and address performance issues with your browser. We also use what we learn from the FHR data in the aggregate to make Firefox better. You can choose to turn data sharing off.
Firefox automatically checks for malicious or forged web pages, broken add-ons, and third-party issued SSL certificates.
Secure Website Certificates: When you visit a secure website (i.e. "https"), Firefox will validate the website's certificate. This may involve communicating with a third-party status provider specified by the certificate. Firefox sends to this third-party information identifying the site's certificate. You can change your preferences, but if you disable the online verification feature, Firefox cannot confirm the identity of the website you are visiting. Turning off this feature may increase the risk of your private information being intercepted. If you encounter an untrusted connection, you can also choose to send Mozilla the associated certificates.
Usage statistics or "Telemetry" is a feature in Firefox that sends Mozilla usage, performance, and responsiveness statistics about user interface features, memory and hardware configuration. Your IP address is also collected as a part of a standard web log. Usage statistics are transmitted using SSL and help us improve future versions of Firefox. Once sent to Mozilla, usage statistics are aggregated and made available to a broad range of developers, including both Mozilla employees and public contributors.
This feature is turned on by default in Nightly, Aurora and Beta builds of Firefox to help those users provide feedback to Mozilla. In the general release version of Firefox, this feature is turned off by default.
See here to learn more about the feature and how to enable or disable it.
When you ask it to, Firefox also connects to Mozilla to provide you with features such as Sync, location services, crash reporting, and add-ons.
Sync: Firefox Sync is a service that allows you to sync your Firefox bookmarks, browsing history, passwords, and settings across all of your devices. If you use the Sync service, you can read the Firefox Sync privacy notice here.
Add-ons: Firefox offers a Get Add-ons page of the Add-ons Manager that features popular add-ons and displays personalized recommendations based on the add-ons you already have installed. To display the personalized recommendations, Firefox sends information to Mozilla, including the list of add-ons you have installed, Firefox version information, and your IP address. This communication only happens when the Get Add-ons area is open and can be turned off by following these instructions.The add-ons manager in Firefox has a search field where you can enter key words to perform searches and Mozilla collects these key word searches, as well as your Firefox version information, locale, and OS to show you recommendations.