Think about what is on your phone right now. Your banking app and the ability to approve transactions. Your email, which is the key to every other account you own. Years of personal photographs. Your contacts — personal and professional. Your messages. Your location history. Your health data. Payment cards saved for online purchases. Access to your cloud storage where your documents and more photos are backed up. Password manager access in many cases.
No single other device in your possession concentrates this much sensitive personal information in one place. Yet most people apply less security to their phone than to their front door. This guide covers every meaningful security setting for both iPhone and Android, in the order of importance.
Screen lock: your first and most basic protection
A screen lock that triggers after a short period of inactivity is the foundational security control on any smartphone. Without one, anyone who picks up your phone has instant access to everything on it.
Set your screen auto-lock to a maximum of 30 seconds to one minute. This is the point at which the phone locks itself if left unattended. On iPhone: Settings → Display & Brightness → Auto-Lock. On Android: Settings → Display → Screen Timeout.
For the lock method itself, Face ID and Touch ID (fingerprint) are both excellent choices for everyday use — they are convenient and meaningfully secure for most threat scenarios. Avoid using a simple four-digit PIN (only 10,000 possible combinations, easily observed by someone watching over your shoulder). A six-digit PIN (one million combinations) is the minimum if you prefer PIN entry. A strong alphanumeric passcode is stronger still.
Never use biometric data alone without a strong backup PIN or password, and be aware that in some legal jurisdictions you can be compelled to unlock a device with biometrics but not with a passcode. If this is relevant to you, understand your rights before travelling to certain destinations.
Operating system updates: the most underrated protection
Both Apple and Google release regular iOS and Android security updates that patch vulnerabilities being actively exploited by attackers. These are not optional improvements — they are critical security fixes, and delaying them leaves you exposed to known, documented vulnerabilities that attackers have working exploit tools for.
Enable automatic updates. On iPhone: Settings → General → Software Update → Automatic Updates, and enable both Download iOS Updates and Install iOS Updates. On Android: Settings → System → System Update, and enable automatic download and installation of updates.
If your phone is old enough that it no longer receives operating system updates from its manufacturer, consider this a significant security concern. Old iPhones and Android phones that have reached end-of-life for software support have unpatched vulnerabilities that will never be fixed. At that point, replacing the device is the only real security solution.
App permissions: the privacy audit you have never done
When you install an application, it requests access to various features and data on your phone — your location, camera, microphone, contacts, photos, calendar, health data, and so on. Many apps request far more access than they genuinely need to function. A torch app that requests access to your contacts is collecting data it has no operational reason to need. A casual game that wants access to your microphone is almost certainly doing something you would not sanction if asked plainly.
Set aside 10 minutes to audit your app permissions. On iPhone, go to Settings → Privacy & Security and work through each category — Location Services, Contacts, Microphone, Camera, Photos, and so on. On Android, go to Settings → Privacy → Permission Manager.
For location specifically, most apps should have this set to “Never” or “Ask Next Time”. The apps that legitimately need your location most of the time (Maps, navigation apps, local weather) can be set to “While Using the App”. Very few apps genuinely need “Always On” location access — check each one that has it and consider whether you actually need it.
App installation: official sources only
The App Store on iPhone and Google Play on Android both have security review processes that, while imperfect, filter out the vast majority of malicious applications before they reach users. Third-party app stores, direct APK downloads from websites, and apps shared as files do not go through these reviews and represent a substantially higher risk of malware infection.
On iPhone, the operating system prevents installation from sources other than the App Store by default. Keep this restriction in place. Do not jailbreak your device — jailbreaking removes the security architecture that protects you from malicious apps and other exploits.
On Android, there is a setting called “Install Unknown Apps” or “Unknown Sources” that controls whether apps can be installed from outside the Play Store. Keep this disabled unless you have a specific, well-understood reason to enable it. If you enable it temporarily for a specific purpose, disable it again immediately afterwards.
Remote wipe and Find My Device
Both iPhone and Android support the ability to remotely locate, lock, and wipe your phone if it is lost or stolen. This is a critical safety net — but only if it is configured before you need it.
On iPhone: Settings → your Apple ID name → Find My → Find My iPhone. Ensure Find My iPhone is enabled, Send Last Location is enabled, and Find My Network is enabled. To use it if your phone is lost, go to icloud.com/find from any device or use the Find My app on another Apple device.
On Android: Go to your Google account at myaccount.google.com → Security → Find My Device. Ensure it is turned on. To use it, go to android.com/find from any browser.
Test these features with your own device now so you know how to use them under the stress of a lost or stolen phone situation. Practice makes the difference between recovering your device and losing it permanently.
Encrypted messaging and secure communications
Standard SMS text messages are not encrypted. They can be intercepted at the network level, accessed by your mobile carrier, and in some cases retrieved by malicious software or compromised devices. For personal communications where privacy matters — financial discussions, medical conversations, personal matters — use an end-to-end encrypted messaging app.
Signal is the gold standard: open source, independently audited, used and recommended by security researchers, journalists, lawyers, and activists worldwide. WhatsApp uses the same encryption protocol as Signal for messages. iMessage is encrypted between Apple devices. For sensitive communications, any of these is vastly preferable to SMS.
Cloud backup
Enable automatic cloud backup on your phone. On iPhone, this means iCloud Backup: Settings → your name → iCloud → iCloud Backup, and enable Back Up This iPhone. On Android, this means Google One backup: Settings → System → Backup, and enable Google One Backup.
A current backup means that if your phone is lost, stolen, damaged, or compromised, everything on it — your photos, contacts, messages, app data, and settings — can be fully restored to a replacement device. Without a backup, device loss often means permanent data loss.