Protects against the following threat(s):
A custom Android-based operating system (often known as a custom ROM) is a popular way to achieve higher levels of privacy and security on your device. This is in contrast to the "stock" version of Android which comes with your phone from the factory, and is often deeply integrated with Google Play Services.
We recommend installing one of these custom Android operating systems on your device, listed in order of preference, depending on your device's compatibility with these operating systems.
AOSP Derivatives¶
GrapheneOS¶
GrapheneOS is the best choice when it comes to privacy and security.
GrapheneOS provides additional security hardening and privacy improvements. It has a hardened memory allocator, network and sensor permissions, and various other security features. GrapheneOS also comes with full firmware updates and signed builds, so verified boot is fully supported.
GrapheneOS supports sandboxed Google Play, which runs Google Play Services fully sandboxed like any other regular app. This means you can take advantage of most Google Play Services, such as push notifications, while giving you full control over their permissions and access, and while containing them to a specific work profile or user profile of your choice.
Google Pixel phones are the only devices that currently meet GrapheneOS's hardware security requirements.
By default, Android makes many network connections to Google to perform DNS connectivity checks, to sync with current network time, to check your network connectivity, and for many other background tasks. GrapheneOS replaces these with connections to servers operated by GrapheneOS and subject to their privacy policy. This hides information like your IP address from Google, but means it is trivial for an admin on your network or ISP to see you are making connections to grapheneos.network, grapheneos.org, etc. and deduce what operating system you are using.
If you want to hide information like this from an adversary on your network or ISP, you must use a trusted VPN in addition to changing the connectivity check setting to Standard (Google). It can be found in 
Settings → Network & internet → Internet connectivity checks. This option allows you to connect to Google's servers for connectivity checks, which, alongside the usage of a VPN, helps you blend in with a larger pool of Android devices.
DivestOS¶
If GrapheneOS isn't compatible with your phone, DivestOS is a good alternative. It supports a wide variety of phones with varying levels of security protections and quality control.
DivestOS is a soft-fork of LineageOS. DivestOS inherits many supported devices from LineageOS. It has signed builds, making it possible to have verified boot on some non-Pixel devices. Not all supported devices support verified boot or other security features.
The status of firmware updates in particular will vary significantly depending on your phone model. While standard AOSP bugs and vulnerabilities can be fixed with standard software updates like those provided by DivestOS, some vulnerabilities cannot be patched without support from the device manufacturer, making end-of-life devices less safe even with an up-to-date alternative ROM like DivestOS.
DivestOS has automated kernel vulnerability (CVE) patching, fewer proprietary blobs, and a custom hosts file. Its hardened WebView, Mulch, enables control-flow integrity for all architectures and network state partitioning, and receives out-of-band updates.
DivestOS also includes kernel patches from GrapheneOS and enables all available kernel security features via defconfig hardening. All kernels newer than version 3.4 include full page sanitization and all ~22 Clang-compiled kernels have -ftrivial-auto-var-init=zero enabled.
DivestOS implements some system hardening patches originally developed for GrapheneOS. DivestOS 16.0 and higher implements GrapheneOS's INTERNET and SENSORS permission toggle, hardened memory allocator, exec-spawning, Java Native Interface constification, and partial bionic hardening patchsets. 17.1 and higher features per-network full MAC address randomization, ptrace_scope control, automatic reboot, and Wi-Fi/Bluetooth timeout options.
DivestOS uses F-Droid as its default app store. We normally recommend avoiding F-Droid, but doing so on DivestOS isn't viable; the developers update their apps via their own F-Droid repository, DivestOS Official. For these apps you should continue to use F-Droid with the DivestOS repository enabled to keep those components up to date. For other apps, our recommended methods of obtaining them still apply.
DivestOS replaces many of Android's background network connections to Google services with alternative services, such as using OpenEUICC for eSIM activation, NTP.org for network time, and Quad9 for DNS. These connections can be modified, but their deviation from a standard Android phone's network connections could mean it is easier for an adversary on your network to deduce what operating system you have installed on your phone. If this is a concern to you, consider using a trusted VPN and enabling the native VPN kill switch to hide this network traffic from your local network and ISP.
Criteri¶
Please note we are not affiliated with any of the projects we recommend. In addition to our standard criteria, we have developed a clear set of requirements to allow us to provide objective recommendations. Ti suggeriamo di familiarizzare con questo elenco prima di scegliere di utilizzare un progetto e di condurre le tue ricerche per assicurarti che si tratti della scelta adatta a te.
- Deve essere un software open source.
- Must support bootloader locking with custom AVB key support.
- Must receive major Android updates within 0-1 months of release.
- Must receive Android feature updates (minor version) within 0-14 days of release.
- Must receive regular security patches within 0-5 days of release.
- Must not be "rooted" out of the box.
- Must not enable Google Play Services by default.
- Must not require system modification to support Google Play Services.