What is a Private Tab in Arc Browser?
Private Tab is Arc’s version of private browsing mode. When enabled, Private Tab prevents the browser from saving any information about your browsing session on your device, such as:
- Browsing history
- Cookies and site data
- Information entered in forms
- Temporary files like caches
Essentially, Private Tab allows you to browse the web anonymously, without leaving a trace of your activity. Once you close the private browsing session, it will be like you were never there.
Key Features of Private Tab
- Does not record browsing history, searches, cookies, site data or entered form data
- Does not leave traces of activity on your device when the session is closed
- Allows browsing in regular tabs while having private tabs open simultaneously
- Private tabs have a distinct dark theme to differentiate them
- Closing the last private tab ends the session completely
How to Use Private Tab
Using Private Tab in Arc is very straightforward.
Opening a Private Tab
To open a new Private Tab:
- Click the “+” button at the bottom of the sidebar
- Select “New Private Tab” from the menu
A new private tab with a dark theme will open. You can now start browsing privately.
Switching Between Modes
You can open and view regular and private tabs simultaneously in Arc. The private tabs are visually distinguished by their darker theme.
To switch between private and regular tabs:
- Click on the tab you want to view to bring it into focus
- Use keyboard shortcuts Cmd+Tab (next tab) and Cmd+Shift+Tab (previous tab) to cycle through tabs
Closing a Private Session
Closing the last open private tab will end the private browsing session in Arc. Any private tabs open will display a warning before closing to avoid accidentally ending your session.
To intentionally end a private session, close all private tabs until you see the confirmation prompt. Click “Close Private Tabs” to end the session and delete all related private data.
Benefits of Private Tab
Arc’s Private Tab offers several benefits:
Browse Anonymously
The primary benefit of Private Tab is the ability to browse anonymously without saving any information about your activity. Your browsing data will not be stored on your device or available to websites.
Protect Sensitive Information
Private Tab allows you to visit sites or enter information without it being recorded and stored. This is useful for protecting sensitive data like passwords, addresses, or credit card numbers.
Avoid Tracking
Many websites use tracking cookies and cache data to record your visits. Private Tab prevents this tracking, allowing you to avoid being followed across the web.
Maintain Separate Browsing Environments
Having private and regular tabs open simultaneously lets you maintain separate browsing environments for different purposes on the same device.
Feel Safe Exploring
The impermanent nature of private browsing mode encourages exploration and curiosity without worrying about embarrassing or inappropriate sites being discovered later.
Private Tab Limitations
While Private Tab offers many benefits, it also has some limitations:
Does Not Offer Full Anonymity
Your browsing in Private Tab is anonymous on your device, but your internet service provider, network, or sites themselves can still potentially see your activity.
Requires Manual Data Entry
Private Tab won’t auto-fill information or remember logins. You’ll need to manually enter details each time you visit sensitive sites.
Some Sites May Not Function Properly
Websites that depend on cookies and site data may not work as expected in a private browsing session.
Private Tabs Don’t Sync Between Devices
Any private tabs open on one device will not be accessible or synced to your other devices.
Can Accidentally Close Tabs
Forgetting you have private tabs open and closing the last one will end your session and delete all data.
Tips for Using Private Tab
To get the most out of Arc’s Private Tab, keep these tips in mind:
- Use Private Tab any time you want to browse without leaving a permanent record of your activity.
- Avoid entering sensitive information on sites you access regularly in normal tabs.
- Bookmark useful sites and login credentials to easily access them in future private sessions.
- Open a regular tab first before starting a private session to avoid losing access to important tabs.
- Pay attention to the dark theme so you can easily tell when you’re browsing privately.
- Close all private tabs when finished to avoid accidental closure losing your data.
Privacy Considerations
While Private Tab protects your privacy in Arc, some general privacy considerations apply:
IP Addresses
Your IP address is still visible to sites you visit, allowing rough geolocation and identification.
Network Monitoring
Your network provider can potentially see your browsing activity, even in private modes.
Browser Fingerprinting
Without countermeasures, sites can use fingerprinting techniques to identify your browser details.
Malware and Spyware
Malicious software could still record your private browsing if installed on your device.
While private modes like Arc’s Private Tab offer additional protection, more advanced tools like VPNs and Tor are required for full anonymity.
Private Tab Implementation
Under the hood, Arc implements Private Tab using a few key techniques to prevent recording browsing data:
In-Memory Storage
Private session data is kept in ephemeral in-memory stores that are deleted when the session ends, rather than written to disk.
Separate Profiles
Private tabs use a separate browser profile from normal tabs to isolate browsing environments.
Disable Caching
Arc disables caching and temp file creation in Private Tab to avoid leaving forensic evidence.
Block Requests
Certain requests like favicon lookups are blocked to prevent data leaks.
Prevent Syncing
Syncing of private tab data across devices is intentionally prevented by Arc.
Detect Leaks
Arc attempts to detect and warn if any private data is accidentally persisted.
Private Tab Security
Maintaining security and preventing data leaks is critical for a private browsing mode. Arc takes several steps to keep Private Tab secure:
Minimal Data Retention
Only the bare minimum data is retained in memory to allow sites to function properly.
No Writes to Disk
Private session data is never written to disk where it could be forensically recovered.
Ephemeral Profiles
Private Tab profiles are ephemeral and reset after each browsing session.
Sync Disabled
Syncing of private data across devices is intentionally blocked to contain the session.
Alerts for Persistence
Arc will alert users if private data is detected as persisting improperly.
No Extension Support
Arc does not allow extensions in Private Tab to prevent data leakage.
Validated Deletion
When a session ends, Arc validates all private data is wiped and unrecoverable.
Private Tab Compared to Incognito Mode
Arc’s Private Tab works similarly to Incognito Mode found in other major browsers like Chrome and Firefox. However, there are some differences:
| Feature | Private Tab | Incognito Mode |
| Does not record history | Yes | Yes |
| Disables caching | Yes | Yes |
| No extension support | Yes | No |
| Separate profile | Yes | Varies |
| Sync disabled | Yes | No |
| Warn on data persistence | Yes | No |
| Validate data deletion | Yes | No |
In summary, Private Tab offers some additional protections compared to traditional Incognito modes, at the cost of extension and sync support.
Private Tab Detection
Websites can employ various methods to attempt to detect when a visitor is using private browsing mode, including:
Storage Detection
Checking if access to localStorage/sessionStorage is denied can reveal a private browser.
IndexedDB Reads
Attempting to read IndexedDB data that would be present can detect a private session.
Cache Existence
Checking for existence of cache data from previous visits indicates a private browser if not found.
Cookie State
A lack of existing first-party cookies can imply a private window.
Fingerprinting Surface
Reduced fingerprinting surface, like missing plugins, reveals private mode.
Media Device Access
Denied access to media devices due to permissions prompts exposes private browsing.
The effectiveness of these methods varies across private browsing implementations and they can often be circumvented.
Why Private Browsing Modes Exist
Private browsing modes like Arc’s Private Tab respond to a few driving factors:
User Demand
People wanted an easy way to browse privately after realizing browsing history was stored.
Secure Behavior
Private tabs encourage more secure browsing by making tracking and monitoring harder.
Reduce Embarrassment
Private tabs allow people to explore the web without fear of judgment based on permanent histories.
Regulatory Pressure
Governments enacted legislation protecting privacy that spurred development of private modes.
Prevent Leaks
Private tabs reduce exposing browsing history to other users of a shared device.
Overall private browsing arose both from consumer demand and a push towards greater privacy and anonymity online.
How Private Browsing Differs Across Browsers
The major web browsers all offer private modes but with varying implementations:
Google Chrome
Chrome’s Incognito Mode uses in-memory storage and prevents syncing data across Google services. However, it allows extensions to remain enabled.
Safari
Safari’s Private Browsing uses Intelligent Tracking Protection to block trackers. Safari also shares cookies between normal and private modes.
Mozilla Firefox
Firefox Private Browsing uses a separate profile and prompts for media permission access. Firefox also allows extensions.
Microsoft Edge
InPrivate mode in Edge does not permit extensions. Edge also lacks alerts if private data persists improperly.
Third-party browsers take varying approaches as well, with Brave offering the strongest privacy protections overall.
Private Browsing on Mobile Devices
Private browsing on smartphones works similarly to desktop implementations:
iOS
Apple’s Safari for iOS provides a private mode that prevents local storage. It uses on-device intelligence to block some trackers.
Android
Chrome for Android’s Incognito prevents recording history, cookies, searches and site data. It persists cached media files after exiting.
Privacy Risks
Despite private modes, mobile devices have additional privacy risks from telemetry data and OS-level tracking.
Using a privacy-focused mobile OS like GrapheneOS on Pixel devices offers stronger protection for mobile users.
Extensions and Private Browsing
Browser extensions can pose privacy risks to private browsing modes by persisting data outside the private scope. Arc handles extensions with Private Tab in a few key ways:
No Extension Support
Arc disables extension functionality completely within Private Tab sessions.
Persistent Storage Access
Extensions could write private data to storage outside the ephemeral private profile.
Page Access
Extensions with page access could leak private data from the session.
Network Requests
Extensions can make network calls with private browsing data.
Overall, Arc’s approach of blocking extensions enhances privacy protections.
Is Private Tab really private?
Private Tab prevents Arc from saving any browsing data locally on your device. However, your internet traffic is still visible to networks/websites.
Does Private Tab work on mobile?
No, Private Tab is currently only available on the Arc desktop browser for macOS and Windows (in beta).
Can websites detect I’m using Private Tab?
Websites can sometimes employ methods to detect private browsing, but Arc tries to prevent many detection techniques.
What data is deleted after a Private Tab session?
Browsing history, cookies, site storage, caches, entered form data, and other temporary files are all deleted after closing all private tabs.
Are extensions supported in Private Tab?
No, Arc disables all extensions while private browsing to prevent potential data leaks through extensions.
The Bottom Line
Arc Browser’s Private Tab mode provides users with a robust private browsing implementation balanced with usability. Key privacy protections like ephemeral profiles and strict data separation allow anonymity while browsing. While not completely hidden from the internet, Private Tab represents a major step forward in putting user privacy first. As pressure grows for tighter data privacy regulations, innovations like Private Tab will only continue improving over time.
