iOS 18.4: what’s new?

In a move atypical for the industry where “postponed” is a much more common label for everything than “released earlier,” Apple gave us iOS 18.4 on March 31, 2025 instead of the promised early April. In this piece, we summarize all the major updates and features the new version brings, and ruminate a bit about whether it’s worth moving up to iOS 18.4 immediately or maybe waiting a couple of weeks for a more stable release is a good idea.

Before reading any further, make sure your device ready for iOS 18.4. The system can run on iPhone 11 and up, and on iPhone SE 2nd generation or later.

iOS 18.4: noteworthy features and updates

Apple has been actively developing and introducing its AI into everything the ecosystem includes, and iOS 18.4 looks like another step towards the ultimate goal of a fully AI-driven operating system. Here are the noteworthy additions to the pack.

Priority notifications: smart alerts that occupy a specially designated portion of the lock screen; they scoop up events that, as the AI behind them believes, deserve your attention above everything else. You can customize these notifications in Settings → Notifications.
Visual intelligence and Image Playground: the former promises enhanced photo analysis capabilities and more accurate recognition of objects and scene elements, the latter, being an AI art generator, now has “Sketch” mode.

App-wise, the iOS 18.4 brings the following:

Vision Pro app: your iPhone is now a discovery tool and a conduit for content that is designed specifically for Apple Vision Pro.
Safari and Mail: Apple’s browser got improved tab management (a more streamlined deal; it is much less painful to sort through dozens of tabs), and Mail was quite considerably redesigned to make it a more convenient alternative to other popular clients and browser-based email apps.

Miscellaneous improvements and additions:

new emoji with bags under eyes (surely one of the top items on the list of features requested by customers);
lossless audio playback for AirPods Max when connected with a wire;
several new languages (German, French, Spanish, Japanese, etc.) in Apple Intelligence;
overall performance and battery life optimization, as already noted by some expert users, which is especially relevant for older devices.

So, upgrade to iOS 18.4 now or wait a bit?

As of this writing, it’s been less than a week since the new version was released, and, while generally praised for the improvements and new stuff mentioned above, it did garner some criticism, too.

Wi-Fi and Bluetooth connectivity issues: some users report difficulties connecting to Wi-Fi networks/Bluetooth pairs and/or staying connected.
CarPlay issues: iOS 18.4 can hinder the iPhone – CarPlay connection and cause problems with playback (distorted audio, etc.).
Reappearing previously deleted apps: some reports have emerged stating that with iOS 18.4 some apps that were removed from the device earlier return to the home screen.
iCloud sync issues: synchronization delays or even failures; not a massively spotted bug, but still noteworthy.

These problems will likely be fixed quite quickly, so if you believe some of them can be a major nuisance for you, postpone the upgrade for a week or so.