With iOS 12, Apple revolutionized notifications by introducing grouped alerts, helping you cut through the clutter to reach important messages like emails or iMessages faster. However, the two grouping options—Automatic and By App—behave differently, impacting your lock screen experience.
Contents: Automatic notification grouping | Grouping notifications by app | What's best for you | Changing and managing notification settings | Cheers, Apple!

Apple's iOS 12 offers two modes for bundling notifications: Automatic and By App. While they might seem similar at first, understanding their nuances ensures a smoother, more efficient workflow. As someone who's managed notifications across countless iOS devices, I've tested both extensively—here's what you need to know.
By default, iOS 12 uses Automatic grouping for all apps. This intelligent system analyzes notifications contextually—no rigid rules, just smart stacking for optimal viewing.
For apps like Messages or WhatsApp, multiple messages from one contact stack together. Alerts from different contacts form separate stacks, even within the same app.
The same applies to tools like Slack, where notifications group by team, channel, or member.

iOS 12 goes further by subcategorizing based on timing or threads. For instance, repeated messages from the same contact at different times appear in distinct stacks. Machine learning refines this over time by learning your interaction patterns, delivering a personalized experience.
Automatic mode excels in most cases but can occasionally stack minor alerts separately, adding minor clutter.

The By App option consolidates all notifications from a single app into one stack. New alerts may appear briefly separately but merge into the stack if ignored.

Since Automatic is default, switch to By App manually per app for simplicity.
iOS 12 empowers per-app customization. Automatic shines for context-rich apps like email, Messages, or Calendar, preserving vital separations. By App suits news, social media, games, cloud storage, or photo apps—avoiding multiple stacks from low-priority alerts.
Test both for heavy-notification apps and choose what minimizes frustration. For urgent apps (Home, Calendar), stick with Automatic to prevent burying key alerts.
In Settings > Notifications, select an app, then choose Grouping under Alerts. No global toggle—configure individually.

Tip: To stop notifications entirely, select None.
Alternatively, swipe left on a notification/stack, tap Manage, then Settings for quick access. "Deliver Quietly" sends alerts silently to Notification Center; "Turn Off" disables them app-wide.

Prior iOS versions overwhelmed screens with notification floods, but iOS 12's dual modes and per-app flexibility restore control. Apple's thoughtful design makes managing alerts intuitive and effective—bravo!