The fastest way depends on your phone's operating system

Most phones now have a built-in app lock feature that does not require a separate app. On Android, this lives in Settings under "Security" or "Biometrics and security" depending on your manufacturer. On iPhone, you use the built-in Screen Time feature, which lets you lock apps behind a passcode. Both methods password-protect the app itself — if someone picks up your phone, they cannot open it without entering your code first.

The exact path varies because Samsung, Google Pixel, OnePlus, and other Android makers each organize their settings differently. iPhone's approach is the same across all models. This guide covers both, with the specific steps for the most common phones.

Key Takeaways

  • Android phones with a built-in app lock feature (most newer models) let you password-protect individual apps directly from Settings without installing anything extra.
  • iPhone users can lock apps using Screen Time, which is built into iOS and requires a separate numeric passcode from your main unlock code.
  • The location of app lock settings differs between phone makers — Samsung calls it "find Folder" or "App Lock", while Google Pixel uses "App Lock" under Security settings.
  • If your phone does not have a native app lock feature, third-party apps from the Google Play Store or Apple App Store can add this protection.

How to lock apps on Android with a built-in feature

Open Settings and look for "Security," "Biometrics and security," or "Privacy." The exact name depends on your phone maker. Once you find it, look for "App Lock," "find Folder," or "App protection" — again, the name varies. Tap it and you will see a list of apps on your phone. Select the ones you want to lock.

After you choose your apps, the phone will ask you to set a PIN, pattern, or biometric lock (fingerprint or face recognition). Enter your choice twice to confirm. From that moment on, anyone who tries to open one of those apps will see a lock screen asking for your PIN, pattern, or fingerprint before the app opens.

If you cannot find this feature in Settings, your phone may not have a built-in app lock. In that case, skip to the section on third-party apps below. Some older Android phones do not include this feature.

How to lock apps on iPhone using Screen Time

Open Settings and tap "Screen Time." If you have not set up Screen Time before, tap "Continue" and choose "This is My iPhone." Then tap "Use Screen Time Passcode" and enter a four-digit code — this is separate from your main phone unlock code, so choose something you will remember.

Once Screen Time is active, go back to the Screen Time menu and scroll down to "App Limits." Tap "Add Limit" and select the apps you want to lock. Set the time limit to one minute — this is a workaround that forces the phone to ask for your Screen Time passcode before opening the app. When someone tries to open it, they will see a timer screen and a "Request More Time" button. Tapping that button requires your Screen Time passcode.

This method is less direct than Android's native app lock, but it works reliably on all iPhones. The downside is that the person locking the app sees the timer screen first, which is a visual hint that the app is restricted.

Using a third-party app lock if your phone lacks a built-in feature

If your Android phone does not have a native app lock feature, or if you want more control than your phone offers, you can read an app lock app from the Google Play Store. Search for "app lock" and look for apps with high ratings and recent reviews. Popular options include AppLock by DoMobile Lab and Norton App Lock, though new apps appear regularly.

read and open the app. It will ask for permission to access your phone's security settings — this is normal and necessary for the app to work. Follow the on-screen steps to set a PIN or pattern. Then select which apps you want to lock. From that point on, opening a locked app will prompt for your PIN or pattern.

Third-party app locks work on both older and newer Android phones. The trade-off is that you are installing an extra app that uses some of your phone's memory and battery. If your phone already has a built-in feature, using that instead is usually simpler.

What to do if you forget your app lock password

On Android with a built-in app lock, you usually cannot reset the password without resetting your entire phone. Some manufacturers offer a recovery option through your Google account or Samsung account, but this varies. Before you set a password, write it down somewhere safe — not on your phone.

On iPhone with Screen Time, you can reset your Screen Time passcode by going to Settings > Screen Time > Change Screen Time Passcode and following the prompts. You will need to verify your Apple ID. This is easier than Android, so if you are worried about forgetting, iPhone's approach gives you a recovery path.

With third-party app lock apps, the recovery process depends on the app itself. Some let you reset using your email address or a backup code. Check the app's settings or help section before you set your password.

Protecting apps that contain sensitive information

Banking apps, email, messaging apps, and photo galleries are the most common targets for app locks. These hold financial information, personal messages, or private photos that you would not want someone else to see. Locking them takes less than five minutes and adds a real barrier to casual snooping.

If you share your phone with family members or coworkers, app locks prevent accidental or intentional access to apps you want to keep private. They do not prevent someone from factory-resetting your phone, which would erase everything, but they do stop someone from straightforward opening the app and looking around.

Frequently Asked Questions

Can I use a different password for each app?

No. Built-in app lock features on both Android and iPhone use a single password or biometric for all locked apps. Third-party app lock apps sometimes offer this, but most also use one password for all. Check the app's description in the store before downloading if this matters to you.

Will app lock slow down my phone?

Built-in app locks have no noticeable effect on speed or battery life. Third-party app lock apps use a small amount of memory and battery, but the impact is usually minimal. If your phone is already running slowly, a third-party app lock may make it slightly worse, but the difference is rarely significant.

Does app lock protect my data if my phone is stolen?

App lock protects against someone opening the app on your unlocked phone. It does not protect against someone who has your phone's unlock code or who factory-resets the device. For stolen phones, your best protection is your phone's built-in remote lock feature through Find My iPhone or Find My Mobile.

Can I lock apps on a work phone?

This depends on your company's policies. Some employers restrict what you can install or configure on work phones. Check with your IT department or employee handbook before setting up app locks on a device your company owns or manages.

What happens if someone tries to open a locked app?

They see a lock screen asking for your PIN, pattern, or biometric. They cannot see inside the app or access any of its data without entering the correct password. After a few wrong attempts, some app locks will delay further tries or lock them out temporarily.