Does Browser Collect Connection Data When Inactive?

Browser Data Collection and Network Information

A browser does not collect information about internet connections when it is completely closed or inactive. When a browser is closed or not running, it cannot access the network and therefore cannot collect data about IP addresses or other network information. However, during partial activity or background processes, the browser may send accumulated data, including the IP address, to websites if the session was not properly terminated.

Table of Contents

• Data Collection with Browser Running
• Background Activity and Service Workers
• IP Address and Its Handling
• Mobile Internet and Wi-Fi Example
• What Websites See
• Protection Measures and Recommendations

Data Collection with Browser Running

When the browser is active and running, it regularly collects various information about the internet connection. According to Google Chrome Enterprise, the browser collects data that doesn’t change frequently once at startup or every 24 hours if the browser remains running. This information includes:

• IP address - the public IP address of your device
• Network settings - connection type, quality of connection
• Location data - geolocation information associated with the IP address
• DNS cache - saved data about previously visited sites

It’s important to note that the browser may maintain active network connections even with inactive tabs for data synchronization, updates, and background tasks.

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Background Activity and Service Workers

Modern browsers use service workers to perform tasks in the background. As noted in the MDN documentation, browsers limit the runtime of service workers to save battery power and protect privacy:

“The browser will likely terminate a service worker if it doesn’t finish handling synchronization within a relatively short time. This is an intentional measure to save battery power and protect user privacy by minimizing the time during which the user’s IP address is exposed to the server while the application is in the background.”

Background activity includes:

• Updating bookmarks and synchronizing data
• Checking for extension updates
• Sending accumulated analytics data
• Processing notifications and push messages

However, even during background operations, the browser typically cannot access new network information without an explicit request.

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IP Address and Its Handling

The IP address is a key part of network information that browsers process. According to New Relic documentation:

“For security reasons, the browser does not save the visitor’s IP address for reporting. The IP address is obtained in the HTTP header from the request to the New Relic collector.”

It’s important to understand that:

• IP address is not saved by the browser for extended periods
• Transmission occurs only during active requests to servers
• Geolocation data may be obtained based on the IP address, but is typically not saved

Browsers send the IP address to websites via HTTP headers with each request, but do not store this information between sessions.

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Mobile Internet and Wi-Fi Example

In the scenario you described:

1. Using mobile internet for tethering to a computer
2. Subsequent use of browsers
3. Connecting via cable to home Wi-Fi without opening the browser

In this situation, the browser will not know about the change in network connection if it is not running. When you close the browser, it ceases all network activities and does not track changes in network settings. When restarting the browser, it will:

• Determine the current IP address (Wi-Fi)
• Use the network settings of the current connection
• Not have access to information about the previous mobile connection

“A browser cannot detect the local IP address or any information about the local network (LAN). Thus, any JavaScript code running in the browser cannot transmit to a website any information about the computer or local network” - Information Security Stack Exchange

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What Websites See

Websites can only get information about your connection during active requests from the browser. When the browser is inactive or closed, websites cannot:

• Determine the current IP address
• Access network settings
• Track changes in connection
• Collect traffic data

However, with an active browser, sites can obtain:

• Your current IP address through HTTP headers
• Information about your internet service provider (ISP)
• Geographical location based on IP
• Data about your browser and operating system

As noted on Privacy.net:

“This tool lists the information that any website, advertising, and widget can collect from your web browser. Such information can be used to identify you and/or track your behavior using methods such as looking up IP addresses and browser fingerprinting.”

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Protection Measures and Recommendations

To protect network privacy when switching connections, it’s recommended to:

1. Use incognito mode - limits data collection about the session
2. Clear cache and cookies after switching networks
3. Block location tracking in browser settings
4. Use a VPN to mask your IP address
5. Regularly update your browser to close vulnerabilities

As discussed on Reddit (r/pcmasterrace):

“If you need any privacy, Apple seems like a reliable option. Safari allows blocking IP address and many other things in private browsing mode.”

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Sources

1. Google Chrome Enterprise - Data Collection
2. New Relic Documentation - Security for Browser Monitoring
3. MDN - Offline and Background Operation
4. Information Security Stack Exchange - Local WiFi Detection
5. Privacy.net - Browser Information Collection
6. Reddit - Chrome Data Collection

Conclusion

A browser does not collect information about internet connections when it is completely closed or inactive. When the browser is closed, the following occurs:

1. No network access - the browser cannot obtain network data
2. IP address is not tracked - the browser does not save information about network connections
3. Websites don’t see changes - without an active browser, websites cannot access new network information

When switching connections (for example, from mobile internet to Wi-Fi without opening the browser), previous and new network information remain isolated. For maximum protection, it’s recommended to use private browsing modes, VPNs, and regularly clear browser data when switching network connections.