Turn Emergency Alerts On or Off
If your OnePlus phone keeps buzzing with AMBER Alerts or extreme threat warnings you never signed up for, the culprit is the built-in emergency alert system, not a third-party app. Each alert category, plus its ringtone and vibration, can be controlled on its own, so you do not have to mute everything at once.
Change Home Screen Wallpaper
If you skipped the wallpaper prompt during initial OnePlus setup, the home screen keeps whatever default image OxygenOS assigned. Many owners only notice later that the pre-installed wallpapers do not match their style and want to use their own photo instead. The setting is not always obvious once the setup wizard is finished.
Set Dark or Light Theme for the Phone App
If the Phone app on your OnePlus always follows the system theme, calls and the dialer can look too bright at night or too dull during the day. You can override this and lock in a fixed light or dark look just for the phone app instead of tying it to the general Android theme setting. The dark option also eases strain on your eyes and can trim battery use on OLED screens.
Allow Messages Through Do Not Disturb
If Do Not Disturb is active on your OnePlus, incoming texts and messaging app pings often vanish into the notification shade instead of alerting you. That is a problem when a contact sends something urgent while you are asleep or in a meeting. The messaging exception setting controls which senders are still allowed to break through.
Set a Lock Screen Message
If your OnePlus gets lost, whoever finds it has no way to reach you unless your name or contact info shows up before the device unlocks. The lock screen normally only displays the time and notifications, nothing personal. A short custom line on the Ambient display can close that gap.
Enable or Disable Screen Lock Sound
Every time you lock your OnePlus with the power button, a short lock tone plays automatically. If that click feels unnecessary or gives away that you're checking your phone in a quiet room, you can turn it off - or bring it back later without touching any other sound setting.
Turn Flashlight On or Off
Fumbling for a separate flashlight app when you need light fast wastes time, and some OnePlus phones do not show a flashlight icon on the lock screen at all. The rear camera flash doubles as a torch, but the toggle sits inside quick settings and is easy to miss if you have never swiped there before.
Enable or Disable Background Data for Apps
If an app keeps draining your mobile data even when you are not actively using it, background data usage is likely still switched on for that app. On OnePlus phones this permission runs separately for every installed app, so a messenger might need it while a rarely used game does not. Turning it off selectively can noticeably cut your monthly data consumption.
Enable or Disable Auto Sign-in for Saved Passwords
If Chrome logs you into a website the moment it loads, without ever asking for a password, Auto sign-in is likely active on your OnePlus phone. It uses account names and passwords stored in the browser to skip manual entry completely. That is convenient, but anyone who picks up your unlocked phone gets the same instant access to those accounts.
Change Default Home Launcher
If your OnePlus phone still opens the stock home screen after installing a new launcher from the Play Store, the wrong app is still set as default. This mix-up shows up when widgets, icons or shortcuts do not match the launcher you expected to use. Switching the default Home app fixes which interface controls your start screen.
Show or Hide Caller ID
When you call someone from your OnePlus, your number usually shows up on their screen by default, following whatever your carrier has set. If you want to call without revealing your number, that behavior sits in a setting most people never touch. On Dual SIM phones, each SIM handles this separately, so the wrong card can leave you exposed even after you think you have hidden your number.
Manage Site Permissions in Chrome
If a website suddenly asks for your location or camera without warning, or a page refuses to load because cookies got blocked, the site permissions inside your OnePlus browser are responsible. Every website can hold its own access rules for cookies, location, camera and microphone, separate from your phone's system settings. Once you have granted or denied access a few times, keeping track of which sites hold which permissions gets confusing fast.
Set a Custom Alarm
If your OnePlus phone only rings with one generic alarm sound at the same time every day, you probably have not set up separate alarms for different days or purposes. The Clock app lets you create individual entries with their own time, name, repetition and tone. Without adjusting these settings per alarm, all your wake-up times end up sharing the same schedule and sound.
Send Read Receipts Toggle
If your chat partners can see a Read label the moment you open their text, the Send read receipts option in the Messages app is turned on. Some people want that confirmation switched off to keep replies private, while others rely on it to know a message actually got through. The setting works independently from delivery notifications and applies to every conversation at once.
Lock Screen Notification Display Options
If your OnePlus lock screen shows full message previews and app icons for anyone standing next to you, private content can leak before the phone is even unlocked. Oxygen OS lets you dial that down, from full notification text to nothing at all. Pick the wrong option and you either expose messages on the lock screen or miss alerts you actually wanted to catch.
Show Old SMS Messages Stored on SIM Card
After switching to a OnePlus phone, older SMS messages from a previous SIM card do not show up automatically in the Messages app. They are still stored in the SIM card memory, not on the phone itself, so the app needs to be pointed to that storage location first. This mostly affects people who used SMS storage on the SIM before switching devices.
SMS Delivery Reports: Enable or Disable
When you send a text message, you often have no way of knowing whether it actually landed on the recipient's phone. On OnePlus phones, a hidden setting can request a delivery report from your carrier for every SMS you send. If that option is turned off, or you are not sure which SIM it applies to on a dual SIM device, you will keep sending messages blind.
Enable System-Wide Captions
If videos in some apps show no subtitles at all, or you want a consistent caption style across your OnePlus phone instead of relying on each app's own subtitle toggle, the system-wide captioning option in Accessibility is the setting you need. This feature works independently from automatic app subtitles and lets you pick a fixed language, text size and caption style. Many users overlook it because it hides deep inside the Accessibility menu instead of the display settings.
Enable or Disable Picture-in-Picture Mode
If a video keeps floating over other apps when you did not ask for it, or a media app refuses to shrink into a small window while you check messages, picture-in-picture permission is likely the cause. This mode lets one app overlay another in a movable box, but each app needs its own permission toggle to use it. Once that toggle gets switched off for an app, the floating window simply stops showing up, even if the app itself supports the feature.
Enable or Disable Accessibility Menu
If the Accessibility Menu button is missing from your navigation bar, shortcuts for Assistant, power control, volume and recent apps are not available in the enlarged panel. The feature depends on a separate permission toggle, so switching it once in the wrong place leaves it off. Turning it back on restores the larger on-screen controls for anyone who relies on simplified navigation.
Enable or Disable USB OTG
When a USB flash drive, mouse, or keyboard connected to your OnePlus phone via USB-C is not detected, USB OTG support is usually switched off in the system settings. Without this option enabled, the phone will not exchange data with external USB accessories even if the hardware itself supports OTG. Leaving OTG active also has a small effect on battery drain when accessories stay plugged in for long periods.
Clear App Cache
When a OnePlus app starts crashing, freezing, or showing outdated content, leftover cache files are often the cause. Temporary data can pile up and overlap over time, leading to glitches that have nothing to do with your actual settings or account. Clearing the cache resets these files without touching your personal data.
Assign a Default SIM Card to a Contact
If your OnePlus phone keeps asking which SIM to use before calling a certain contact, that contact has no fixed calling SIM set. On dual SIM setups this means every outgoing call to them needs a manual choice, even if you always use the same line for that person.
Enable or Disable Location (GPS)
If regional weather widgets show the wrong city or navigation apps cannot find your position, Location access on your OnePlus phone might be turned off. Location runs by default to support GPS-based features, but constant background tracking also drains the battery faster than expected. You can check the current status and switch it directly from the quick settings panel or the main settings menu.