Apple iOS 18
What the default settings do
iOS 18 continues Apple’s pattern of enabling several privacy features out of the box. App Tracking Transparency prompts apps before they can track you across other companies’ apps and websites. Siri processes many requests on-device, and Safari blocks known cross-site trackers by default.
However, several defaults still share data with Apple or leave collection enabled. Analytics are sent to Apple unless you opt out, personalized ads are on by default in Apple apps, and Significant Locations quietly logs places you visit. Communication Safety is enabled by default for children in Family Sharing, and Siri data processing has expanded with Apple Intelligence features.
A reasonable privacy baseline
These settings are found in the Settings app on your iPhone.
Privacy & Security
Tracking → Allow Apps to Request to Track → Off
This automatically denies all tracking requests from apps. When set to Off, apps receive a blank identifier instead of your device's advertising ID. You will not see tracking permission prompts.
Analytics & Improvements → Share iPhone Analytics → Off
Stops sending daily diagnostics and usage data to Apple. This includes information about hardware, OS configuration, and how you use your device.
Analytics & Improvements → Improve Siri & Dictation → Off
Prevents audio recordings and transcripts of Siri interactions from being stored by Apple for quality review.
Analytics & Improvements → Share with App Developers → Off
Stops sending crash data and usage statistics from third-party apps to their developers through Apple.
Analytics & Improvements → Improve Apple Intelligence → Off
Prevents data from Apple Intelligence features from being used to train or improve Apple's models. Most Apple Intelligence processing happens on-device, but this setting controls whether results are shared back with Apple.
Apple Advertising → Personalized Ads → Off
Apple still shows ads in the App Store, Apple News, and Stocks. Turning this off means those ads are not based on your activity, interests, or App Store searches.
Location Services
Location Services → System Services → Significant Locations → Off
Stops your iPhone from recording places you visit frequently. This data is encrypted and stored on-device, but disabling it prevents the log from being created.
Location Services → System Services → iPhone Analytics → Off
Prevents location data from being included in analytics reports sent to Apple.
Location Services → System Services → Product Improvement → Off
Stops Apple from using your location data to improve Apple Maps, routing, and other location-based products.
Per-app location access → Review and set to "While Using the App" instead of "Always" where practical
Most apps work correctly with location access only while they are open. Review the list under Privacy & Security → Location Services and adjust apps individually.
Siri & Apple Intelligence
Siri & Search → Siri & Dictation History → Delete Siri & Dictation History
Removes any Siri interaction data currently stored on Apple's servers. This is a one-time action rather than a toggle.
Siri & Search → per-app "Learn from this App" toggles → Review and disable for apps you consider sensitive
Siri indexes content from apps to power suggestions and search. You may want to turn this off for banking, health, or messaging apps where the content is personal.
Safari
Apps → Safari → Prevent Cross-Site Tracking → On (on by default)
Blocks third-party cookies and cross-site tracking using Intelligent Tracking Prevention.
Apps → Safari → Hide IP Address → From Trackers
Hides your IP address from known tracking domains. If you subscribe to iCloud+, this uses Private Relay. Otherwise it relies on local processing.
Apps → Safari → Privacy Preserving Ad Measurement → Off
This feature lets websites measure ad effectiveness without identifying you personally. It is a privacy-respecting approach to ad measurement, but turning it off prevents any ad attribution data from being shared.
Communication Safety
Screen Time → Communication Safety → On (on by default for children's accounts)
In iOS 18, Communication Safety is enabled by default for accounts belonging to children in Family Sharing. It detects nudity in photos received in Messages and other apps, blurring images and showing a warning. All detection happens on-device. No data is sent to Apple or to parents. Leaving this at the default is reasonable.
Lockdown Mode
Privacy & Security → Lockdown Mode → Off (leave at default for most people)
Lockdown Mode significantly restricts device functionality to reduce the attack surface against targeted spyware. It blocks most message attachment types, disables many web technologies in Safari, and restricts incoming connections. This setting is designed for journalists, activists, and others who face state-sponsored threats. Most people should leave it off.
Trade-offs
- Turning off Significant Locations means features like predictive commute times in Maps and some Siri suggestions based on location patterns will not work.
- Disabling personalized ads does not reduce the number of ads in Apple apps - only their relevance to you.
- Setting all apps to “While Using” for location may mean some apps cannot alert you based on your location in the background. Weather widgets and fitness apps are common examples.
- Disabling analytics means Apple receives less data to diagnose bugs and performance issues that may affect your device model.
- Turning off “Learn from this App” for specific apps means Siri will not surface content from those apps in search or suggestions.
- Disabling Privacy Preserving Ad Measurement removes a privacy-friendly alternative to more invasive tracking methods. Some view keeping it on as supporting a better ad ecosystem.
Who should not change these settings
- If you find Siri location-based suggestions valuable (such as estimated travel times and departure alerts), keeping Significant Locations on is reasonable. The data stays encrypted on your device.
- If you use apps that rely on background location access (such as Find My Friends, fitness trackers, or home automation), setting those specific apps to “Always” makes sense.
- If you want to help Apple improve its products and services and are comfortable with the data collected, leaving analytics on is a valid choice.
- If you want to support privacy-respecting ad measurement standards over traditional invasive tracking, keeping Privacy Preserving Ad Measurement on is a reasonable position.
- If you face credible threats of targeted surveillance, Lockdown Mode may be worth enabling despite its restrictions.