Android and iOS are the two most popular mobile operating systems worldwide, with a combined market share of 99.65%. You may think that you can’t go wrong with either option when it comes to security. However, popularity doesn’t equal security, and other operating systems, although not as mainstream, could be a better fit for your needs.
In this guide, we’ll help you find the most secure operating system for mobile phones by reviewing four top options. We’ll discuss their key features, potential drawbacks, and user impressions to provide an objective overview of their overall performance.
Secure OS for Mobile Phones: What To Look For
Every mobile operating system offers some options to protect your device, account, and data, such as a screen lock or backups. Security-oriented operating systems provide more advanced features, including:
- Encryption: Robust end-to-end encryption protocols that protect data at rest and in transit minimize the risk of unauthorized access, interception, and exploitation. They ensure only the sender and the recipient can read the content of a message.
- Frequent security updates and long-term support: Ongoing security maintenance protects your device from evolving mobile security threats, and long-term support ensures it doesn’t become obsolete for years to come.
- Enhanced app permission controls: The ability to manage which apps can access the internet or your device’s hardware sensors (such as the microphone or camera) enhances your privacy and lowers the risk of data leaks.
- Stronger authentication methods: Setting longer passwords, PIN scrambling, and leveraging biometric authentication help you ensure data safety in case of device theft or loss.
Most Secure Mobile OS: 4 Top-Rated Options
The mobile OS market has been spreading rapidly, and dozens of options are now available. We’ve shortlisted the following four security-focused operating systems and provided detailed overviews of their features and potential drawbacks:
- GrapheneOS
- LineageOS
- CalyxOS
- PureOS
1. GrapheneOS
GrapheneOS is an open-source mobile OS that prioritizes privacy and security. It’s a hardened version of Android, with added protections designed to minimize vulnerabilities.
Unlike stock Android, GrapheneOS doesn’t include any Google services. The reasoning behind this is simple—Google is known to collect a frightening amount of personal data from users.
Besides being de-Googled, GrapheneOS boasts other robust security and privacy features, including:
- Attack surface reduction: Unknown vulnerabilities (those that haven’t been discovered or documented) are mitigated by minimizing possible entry points that attackers could use to access the system. This is achieved by stripping unnecessary code to make more features optional or disabling certain functions (like Bluetooth or NFC) when the screen is locked or after a specific time.
- Advanced sandboxing: Play Services can be installed as fully sandboxed apps without special privileges to prevent unauthorized data access.
- Network permission toggle: It’s possible to choose whether specific apps can connect to available networks.
- Storage scopes: When this feature is enabled for a specific app, it tricks it into thinking it has all storage permissions when it doesn’t. The idea is to prevent the app from accessing files it didn’t create, which reduces the risk from malicious apps.
Users are generally happy with the system’s functionalities, but there are some drawbacks to consider. For example, some users claim that the banking apps often don’t function properly. A more significant disadvantage is limited compatibility—GrapheneOS only works with Google Pixel devices.
2. LineageOS
LineageOS is another Android-based OS with enhanced privacy and security options. It is well-known for its smooth, bloat-free user experience. You get only the core apps (like the browser, gallery app, and music player) preinstalled by default. The minimalistic design of stock apps and the lack of excessive toggles and buttons also contribute to a smooth experience.
LineageOS also offers exceptional customizability—you can personalize status bar icons, app icons, and permissions to create an environment that suits your preferences.
The most significant benefit of LineageOS is that it doesn’t come with Google services (unless you add them). This is important for privacy-conscious users concerned about Google’s predatory data collection practices.
Other LineageOS advantages include:
- Frequent security patches and updates: Your device will remain secure and up-to-date for a long time.
- Wide device compatibility: LineageOS works on numerous devices from various brands, including Samsung, LG, Xiaomi, and Motorola.
Users happy with LineageOS particularly enjoy being able to install the latest software on older devices, thus extending their lifespan.
A potential issue is that some people may not enjoy the minimalist design, especially those used to stock Android or a different OS. More importantly, LineageOS doesn’t offer robust security options like GrapheneOS, so it’s not a suitable option for those who require stronger safeguards for their data and accounts.
3. CalyxOS
CalyxOS is an Android-based OS that improves security and privacy by replacing the potential weaknesses of stock Android with more powerful and safer alternatives.
Like many other secure operating systems, CalyxOS ensures that Google Services don’t run in the background, uploading your personal info and location to Google Servers. Instead, the OS lets you set up microG, an open-source replacement for Google Play Services that doesn’t involve location tracking or advertising. Of course, you don’t have to use microG at all—CalyxOS can work in the 100% de-Googled mode.
The table below outlines some other features CalyxOS offers:
CalyxOS works on various Google Pixel, Fairphone, and Motorola phones.
As far as reviews go, they’re mostly positive—users particularly mention that switching from stock Android to CalyxOS is smooth since the systems are similar. A potential drawback is that some apps (such as those for banking) that heavily rely on Google may not work properly or at all on CalyxOS.
4. PureOS
PureOS is a privacy-focused open-source operating system based on Linux. It’s an alternative to iOS and Android that:
- Gives you more control over your device
- Doesn’t involve ads, trackers, or corporate surveillance
Unlike some commercial operating systems that harvest your data, analyze your activity, and share it with third parties, PureOS offers protection because it’s:
Some of the features you’ll get with PureOS are:
- Clean interface: An easy-to-use interface improves user experience, even for those new to Linux.
- Firefox-based browser: A Firefox-based browser with tracker blocking ensures nobody is monitoring your online activity.
- PureOS Store: An app marketplace features only vetted, open-source, privacy-respecting apps for enhanced security.
- No forced updates: Updates are optional, which is particularly convenient for individuals with a custom setup or those who want greater control.
PureOS isn’t just a secure OS for mobile phones—it’s available for PCs and laptops. The problem is its compatibility; the operating system works only on Purism mobile devices. As for PCs, you can install it on most x86-based non-Purism computers.
The Verdict: What Is the Most Secure Mobile Operating System?
All operating systems we’ve discussed offer advanced security options to protect your online activity and personal information. Choosing the most secure OS for mobile devices often comes down to your idea of security and general preferences.
If your priority is a de-Googled OS, GrapheneOS, CalyxOS, and LineageOS are all excellent options. You might prefer GrapheneOS if you’re specifically focused on more robust options, such as advanced sandboxing and the ability to customize network permissions for individual apps.
When deciding, you should also take into account compatibility—for example, LineageOS supports devices from different manufacturers, while GrapheneOS is limited solely to Google Pixel phones.
The basis of the OS is another significant consideration. GrapheneOS, LineageOS, and CalyxOS are based on Android, but if you’re a Linux fan, you may prefer PureOS.
Are Android and iOS Not Secure Enough?
Both Android and iOS offer security options like:
- Robust encryption
- App permissions
- Biometric authentication
- Regular security updates
Despite these features, both operating systems only scratch the surface of security capabilities. Android and iOS collect user data for various purposes, from targeted advertising to improving their services, which could make some individuals feel like they have no privacy. You have some control over data collection, but you can’t disable it completely.
If you don’t mind this, Android and iOS can be suitable options, especially since they’re popular, user-friendly, and easily integrate with many other devices and apps.
Take Your Security Beyond the Operating System
Choosing a secure mobile operating system you’re comfortable with is an important step toward enhanced account and data protection. However, even the most secure operating system can’t protect you from vulnerabilities introduced at the network level, such as:
- SIM swapping
- Phishing
- Data breaches
- Malware
Your mobile carrier is supposed to have numerous security and privacy policies and features in place to defend your device from such threats. The reality is different—major carriers like AT&T, Verizon, and T-Mobile don’t seem equipped to counter cyber attacks. In recent years, we’ve seen numerous telco data breaches, and all commercial carriers have been targeted.
For instance, the 2024 Salt Typhoon cyberattack hit telco providers across the U.S., highlighting systematic vulnerabilities and outdated infrastructure in telecommunications networks.
To avoid becoming a victim of one of these attacks, your best bet is to steer clear from commercial carriers. Instead, pair your secure mobile operating system with Cape—a carrier that prioritizes privacy and enhances network-level security.
Cape: Maximum Security, Zero Compromise
As a privacy-first mobile carrier, Cape has unique capabilities that shield your device, account, and data from security threats.
First and foremost, Cape collects only the data it needs, reflecting its minimal trust requirements. Unlike major carriers, which require your name, location, email, and other personal info, Cape only asks for your phone number. Any data we do receive is deleted after 60 days, and we never sell your info to third parties.
Cape is also the only privacy-first mobile carrier that runs its own mobile network, designed to replace Big Telcos’ weak legacy architecture. This results in a secure channel that manages all domestic or international communication and is far more resistant to network attacks.
Here are some other security features you’ll get with Cape:
You get all security options and unlimited 4G and 5G data, texts, and calls for $99/month—there are no extra taxes, hidden costs, or contracts to worry about.
Get Started With Cape
All you need to create your Cape account and ensure enhanced network security is an eSIM-compatible device. To sign up, visit cape.co/get-cape.
Want to purchase a device with a secure OS? You can visit http://shop.cape.co/ to buy phones with GrapheneOS pre-installed, and claim long-term savings on your Cape plan.
To further support your online privacy and safety, Cape partners with Proton to offer subscribers Proton Unlimited or Proton VPN Plus for just $1 for six months.
