Firefox Fast & Private Browser Security & Privacy Scorecard
Android
Browsing activity stays largely on the device, with strong protections applied by default. Install referral data is shared with Adjust and Google to track how the app was discovered, and crash reports may reach Sentry. Notification delivery uses Firebase, but browsing history is not sent there.
Best for
Everyday browsing with strong built-in protections
Findings
- 0 critical
- 1 high
- 3 medium
- 1 low
- 0 info
0 issues identified across security and privacy analysis.
Top security issues
- Firebase API Key Exposed in Resources
- Plaintext Canary Phrases in SharedPreferences
- Adjust App Token Exposed in Code
Top privacy issues
- Adjust Tracking Without User Consent (GDPR Violation)
- Sentry Breadcrumbs May Contain Personally Identifiable Information
- Plaintext Attribution Data in SharedPreferences
Full analysis
Firefox Fast & Private Browser
Security: 100/100 | Privacy: 90/100
What This Means for You
Browsing activity stays largely on the device, with strong protections applied by default. Install referral data is shared with Adjust and Google to track how the app was discovered, and crash reports may reach Sentry. Notification delivery uses Firebase, but browsing history is not sent there.
Recommendation: Very Secure
Best For: Everyday browsing with strong built-in protections
Key Findings
Data Security - 2 findings (1 medium, 1 low)
Network Security - 1 finding (1 low)
Code Safety - 0 findings
Privacy - 4 findings (1 high, 3 medium)
Privacy Concerns
What Data is Collected
- Install referral data (how the app was discovered) is collected at first launch via Google Play and Adjust.
- Crash and error reports, which may include device details and session information, can be sent to Sentry.
- Firebase receives only what is needed to route push notifications to the device. Browsing history is not included.
Third-Party Data Sharing
| Service | Purpose | Data Shared |
|---|---|---|
| Adjust | Install attribution | Referral source, device identifiers |
| Google Play Install Referrer | Install attribution | Referral source data |
| Sentry | Crash reporting | Crash logs, device details |
| Firebase (FCM) | Push notifications | Notification routing data only |
| OkHttp | HTTP client library | Handles outbound network connections |
Understanding the Scores
| Category | Score |
|---|---|
| Security | 100/100 |
| Privacy | 90/100 |
| Data Security | 100/100 |
| Network Security | 100/100 |
| Code Safety | 100/100 |
| Data Collection | 92/100 |
| Data Sharing | 95/100 |
| User Control | 92/100 |
Positive Security Features
- Browsing history and activity are not transmitted to analytics or advertising services.
- Push notifications are routed without exposing browsing data to Firebase.
- Strong privacy protections are active by default, with no manual configuration required.
Areas for Improvement
- Install attribution services receive information about how the app was discovered. Adjusting device ad tracking preferences can reduce this data sharing.
- Crash reports sent to Sentry may include session details. The app's privacy settings may offer an option to opt out of diagnostic data sharing.
- A small number of privacy-related data handling practices could be made more transparent, particularly around what is shared with attribution partners at install time.
About This Analysis
This scorecard is based on analysis of the app's code, network configuration, and data handling practices.
App Details
- App: Firefox Fast & Private Browser
- Package: org.mozilla.firefox
- Version: 147.0.1
- Scan Date: January 21, 2026
Versions & scan history
| Scan | Date | Overall score |
|---|---|---|
| #3 (current) | 95/100 | |
| #1 | 85/100 |