General: Forums subtopic: App & System Services > Processes & Concurrency Forums tag: Background Tasks Background Tasks framework documentation UIApplication background tasks documentation ProcessInfo expiring activity documentation Using background tasks documentation for watchOS Performing long-running tasks on iOS and iPadOS documentation WWDC 2020 Session 10063 Background execution demystified — This is critical resource. Watch it! [1] WWDC 2022 Session 10142 Efficiency awaits: Background tasks in SwiftUI WWDC 2025 Session 227 Finish tasks in the background — This contains an excellent summary of the expected use cases for each of the background task types. iOS Background Execution Limits forums post UIApplication Background Task Notes forums post Testing and Debugging Code Running in the Background forums post Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" [1] Sadly the video is currently not available from Apple. I’ve left the link in place just in case it comes back.

I regularly see questions, both here on the Apple Developer Forums and in my Day Job™ at DTS, that are caused by a fundamental misunderstanding of how background execution works on iOS. These come in many different variants, for example: How do I keep my app running continuously in the background? If I schedule a timer, how do I get it to fire when the screen is locked? How do I run code in the background every 15 minutes? How do I set up a network server that runs in the background? How can my app provide an IPC service to another one of my apps while it’s in the background? How can I resume my app in the background if it’s been ‘force quit’ by the user? The short answer to all of these is You can’t. iOS puts strict limits on background execution. Its default behaviour is to suspend your app shortly after the user has moved it to the background; this suspension prevents the process from running any code. There’s no general-purpose mechanism for: Running code continuously in the background Running code at some specific time in the background Running code periodically at a guaranteed interval Resuming in the background in response to a network or IPC request [1] However, iOS does provide a wide range of special-purpose mechanisms for accomplishing specific user goals. For example: If you’re building a music player, use the audio background mode to continue playing after the user has moved your app to the background. If you’re building a timer app, check out the AlarmKit framework. On older systems, use a local notification to notify the user when your timer has expired. If you’re building a video player app, use AVFoundation’s download support. Keep in mind that the above is just a short list of examples. There are many other special-purpose background execution mechanisms, so you should search the documentation for something appropriate to your needs. IMPORTANT Each of these mechanisms fulfils a specific purpose. Do not attempt to use them for some other purpose. Before using a background API, read clause 2.5.4 of the App Review Guidelines. Additionally, iOS provides some general-purpose mechanisms for background execution: To resume your app in the background in response to an event on your server, use a background notification (aka a ‘silent’ push). For more information, see Pushing background updates to your App. To request a small amount of background execution time to refresh your UI, use the BGAppRefreshTaskRequest class. To request extended background execution time, typically delivered overnight when the user is asleep, use the BGProcessingTaskRequest class. To continue user-visible work after the user has left your app, use the BGContinuedProcessingTask class. To prevent your app from being suspended for a short period of time so that you can complete some user task, use a UIApplication background task. For more information on this, see UIApplication Background Task Notes. To download or upload a large HTTP resource, use an URLSession background session. All of these mechanisms prevent you from abusing them to run arbitrary code in the background. As an example, consider the URLSession resume rate limiter. For more information about these limitations, and background execution in general, I strongly recommend that you watch WWDC 2020 Session 10063 Background execution demystified [2]. It’s an excellent resource. Specifically, this talk addresses a common misconception about the app refresh mechanism (BGAppRefreshTaskRequest and the older background fetch API). Folks assume that app refresh will provide regular background execution time. That’s not the case. The system applies a range of heuristics to decide which apps get app refresh time and when. This is a complex issue, one that I’m not going to try to summarise here, but the take-home message is that, if you expect that the app refresh mechanism will grant you background execution time, say, every 15 minutes, you’ll be disappointed. In fact, there are common scenarios where it won’t grant you any background execution time at all! Watch the talk for the details. [1] iOS 26 introduced support for general-purpose IPC, in the form of enhanced security helper extensions. However, these can only be invoked by the container app, and that means there’s no background execution benefit. [2] Sadly the video is currently not available from Apple. I’ve left the link in place just in case it comes back. When the user ‘force quits’ an app by swiping up in the multitasking UI, iOS interprets that to mean that the user doesn’t want the app running at all. So: If the app is running, iOS terminates it. iOS also sets a flag that prevents the app from being launched in the background. That flag gets cleared when the user next launches the app manually. This gesture is a clear statement of user intent; there’s no documented way for your app to override the user’s choice. Note In some circumstances iOS will not honour this flag. The exact cases where this happens are not documented and have changed over time. Finally, if you have questions about background execution that aren’t covered by the resources listed here, please open a new thread on the forums with the details. Put it in a reasonable subtopic and tag it appropriately for the technology you’re using; if nothing specific springs to mind, use Background Tasks. Also, make sure to include details about the specific problem you’re trying to solve because, when it comes to background execution, the devil really is in the details. Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" Change history: 2026-01-09 Added a reference to AlarmKit. Added a reference to BGContinuedProcessingTask. Add a footnote about IPC and another one about WWDC 2020 Session 10063. Made other minor editorial changes. 2024-03-21 Added a discussion of ‘force quit’. 2023-05-11 Added a paragraph that explains a common misconception about the app refresh mechanism. Made other minor editorial changes. 2021-08-12 Added more entries to the common questions list, this time related to networking and IPC. Made minor editorial changes. 2021-07-26 Extended the statement about what’s not possible to include “running code periodically at a guaranteed interval”. 2021-07-22 First posted.

Hello! I have read most of the "Background Tasks Resources" here https://developer.apple.com/forums/thread/707503 - but still have a few questions that I need clarified. To provide our context, our usecase is that our user wants to upload files to our servers. This is an active decision by the user to initiate the upload, but we also want make sure the files are uploaded, even if the user chooses to background our app. If we use a URLSession.backgroundto initiate the uploadTask, I understand that we are passing it of to the urlsession deamon to handle the upload. Which is great, if the user chooses to background our app. But, what if they just stay with the app in the foreground? Will it start uploading immediately? Can we expect the same latency that a standard URLSession will provide? And the potential delay will only occur if they actually background our app. Also, what happens if a background upload is in-progress and the user enters our app again? Will it gain priority, and run with similar latency as standard URL session? I.e., can we just always rely on using a background session, or should we kick of a beginBackgroundTask with a standard URL session, and only trigger a background uploadTask if we do not finish the standard upload before getting told we are about to get killed? A different question. I know there is the rate-limit delay added if we trigger multiple background URL tasks. Does that effect the following use case? We would like to send an additional HTTP request to our servers when the upload is completed, to notify it of the completion, but are we allowed to do that when the app is woken from the background? So, basically calling .dataTask from handleEventsForBackgroundURLSession for example?

Hell Apple Developer Community, I need help with the Upload of my Project to AppStore Connect. I’ve got an Error Message, that tells me something is missing in the Info.plist file. Can somebody help me?

I have an app that uses background audio recording. From what others say, I have enabled the audio background mode to keep the audio session active, and this worked. But when submitting the app to the app store, the app was rejected because the audio background mode is only supposed to be used for audio playback. How do I create this background mode while following Apple's guidelines?

Greetings.I have an app today that uses multipeer connectivity extensively. Currently, when the user switches away from the app, MPC disconnects the session(s) - this is by design apparently (per other feedback). I'd like to hear if anyone has experimented with iOS9 multitasking / multipeer and whether MPC sessions can stay alive?Thanks

Hi, I have a couple questions about background app refresh. First, is the function RefreshAppContentsOperation() where to implement code that needs to be run in the background? Second, despite importing BackgroundTasks, I am getting the error "cannot find operationQueue in scope". What can I do to resolve that? Thank you. func scheduleAppRefresh() { let request = BGAppRefreshTaskRequest(identifier: "peaceofmindmentalhealth.RoutineRefresh") // Fetch no earlier than 15 minutes from now. request.earliestBeginDate = Date(timeIntervalSinceNow: 15 * 60) do { try BGTaskScheduler.shared.submit(request) } catch { print("Could not schedule app refresh: \(error)") } } func handleAppRefresh(task: BGAppRefreshTask) { // Schedule a new refresh task. scheduleAppRefresh() // Create an operation that performs the main part of the background task. let operation = RefreshAppContentsOperation() // Provide the background task with an expiration handler that cancels the operation. task.expirationHandler = { operation.cancel() } // Inform the system that the background task is complete // when the operation completes. operation.completionBlock = { task.setTaskCompleted(success: !operation.isCancelled) } // Start the operation. operationQueue.addOperation(operation) } func RefreshAppContentsOperation() -> Operation { }

Currently I am trying to find a work around to fetch data from server and update user defaults when app is forced quit. Can anyone suggest for this ?

I coded two demo websites as follows (both written in NextJS): Website 1: I coded an interval counter that increments every 1 second. Website 2: I used the MediaRecorder API (described in the WebKit documentation: https://webkit.org/blog/11353/mediarecorder-api/). In the ondataavailable function, I periodically send a blob (once every 1 second) to my server. In the backend, I coded a POST API to upload this blob. I noticed that with website 1, the interval doesn't work when I run Safari in the background, even on iOS and iPadOS. However, website 2 works, meaning it still calls my API normally (I tried running Safari in the background for about 1-2 hours and it worked). So, does this mean Apple allows native APIs like MediaRecorder and its callbacks to run in the background?

Currently, I have implemented local cache update with server data when app is killed using Push Notification and Notification Service Extension. So it works even the app is killed by the user, but I wanted to know whether this is app review safe work around or not as I am not finding any documentation for this.

I implemented BGContinuedProcessingTask in my app and it seems to be working well for everyone except one user (so far) who has reached out to report nothing happens when they tap the Start Processing button. They have an iPhone 12 Pro Max running iOS 26.1. Restarting iPhone does not fix it. When they turn off the background processing feature in the app, it works. In that case my code directly calls the function to start processing instead of waiting for it to be invoked in the register block (or submit catch block). Is this a bug that's possible to occur, maybe device specific? Or have I done something wrong in the implementation? func startProcessingTapped(_ sender: UIButton) { if isBackgroundProcessingEnabled { startBackgroundContinuedProcessing() } else { startProcessing(backgroundTask: nil) } } func startBackgroundContinuedProcessing() { BGTaskScheduler.shared.register(forTaskWithIdentifier: taskIdentifier, using: .main) { @Sendable [weak self] task in guard self != nil else { return } startProcessing(backgroundTask: task as? BGContinuedProcessingTask) } let request = BGContinuedProcessingTaskRequest(identifier: taskIdentifier, title: title, subtitle: subtitle) request.strategy = .fail if BGTaskScheduler.supportedResources.contains(.gpu) { request.requiredResources = .gpu } do { try BGTaskScheduler.shared.submit(request) } catch { startProcessing(backgroundTask: nil) } } func startProcessing(backgroundTask: BGContinuedProcessingTask?) { // FIXME: Never called for this user when isBackgroundProcessingEnabled is true }

Our app will launch automatically in the background，Doubt is the result of background fetch ，so we cancel the background modes setting of the background fetch,but we still can see the performFetchWithCompletionHandler method called when app launch in the background。Background launch will cause some bugs in our app. We don't want the app to start in the background. We hope to get help

Hello, This is my first post in the forums, and I'm still learning my way with iOS Development and Swift. My apologies if the formatting is not correct, or If I'm making any mistakes. I'm currently trying to implement an iOS App where the device needs to share the location with my server via an API call. The use case is as follows: the server expects location updates to determine if a device is inside/outside a geofence. If the device is stationary, no locations need to be sent. If the device begins moving, regardless of whether the app is in foreground, background, or terminated, the app should resume posting locations to the server. I've decided to use the CLLocationUpdate.liveUpdates() stream, together with CLBackgroundActivitySession(). However, I have not been able to achieve the behavior successfully. My app either maintains the blue CLActivitySession indicator active, regardless of whether the phone is stationary or not, or kills the Indicator (and the background capability) and does not restore it when moving again. Below I've attached my latest code snippet (the indicator disappears and does not come back). // This method is called in the didFinishLaunchingWithOptions func startLocationUpdates(precise: Bool) { // Show the location permission pop up requestAuthorization() // Stop any previous sessions stopLocationUpdates() Task { do { // If we have the right authorization, we will launch the updates in the background // using CLBackgroundActivitySession if self.manager.authorizationStatus == .authorizedAlways { self.backgroundActivity = true } else { self.backgroundActivity = false self.backgroundSession?.invalidate() } // We will start collecting live location updates for try await update in CLLocationUpdate.liveUpdates() { // Handle deprecation let stationary = if #available(iOS 18.0, *) { update.stationary } else { update.isStationary } // If the update is identified as stationary, we will skip this update // and turn off background location updates if stationary { self.backgroundSession?.invalidate() continue } // if background activity is enabled, we restore the Background Activity Session if backgroundActivity == true { self.backgroundSession = CLBackgroundActivitySession() } guard let location = update.location else { continue } // Do POST with location to server } } catch { print("Could not start location updates") } } } I'm not sure why the code does not work as expected, and I believe I may be misunderstanding how the libraries Work. My understanding is that the liveUpdates stream is capable of emitting values, even if the app has gone to the background/terminated, thus why I'm trying to stop/resume the Background Activity using the "stationary" or "isStationary" attribute coming from the update. Is the behavior I'm trying to achieve possible? If so, I'm I using the right libraries for it? Is my implementation correct? And If not, what would be the recommended approach? Regards

Hello everybody! I'm currently working on a Bluetooth Low Energy Sync that is using BGTaskScheduler & successfully running periodically in the Background on iOS 26. I did watch this years WWDC Session 227 (Finish tasks in the background) & follow the recommendations as suggested. Currently, the App is only using 37 Mb (iPhone 12 mini) & no Location or other services are running in Background. However, when opening Safari & scrolling through some webpages, the App is killed because of "Terminated due to memory issue". I profiled the App & followed advice when it comes to reducing the memory footprint of the App. Are there any additional steps I can take to prevent the App being killed? Are there any recommendations for periodically scheduled Tasks when it comes to the Interval? Do more frequent Tasks (30min compared to one or two hours) have any impact? I tried many different schedules but none seem to make a difference. From my observation, the App is first suspended & eventually killed because of the Memory Pressure. Any hints, suggestions or recommendations are highly appreciated! Thanks a lot for the support!

I've tuned my task to be decently resilient, but I found a few issues that caused it to expire regularly. excessive CPU usage -> I'm actually running it behind ReactNative, and I found an issue where I was still updating ReactNative and thus it was keeping it alive the entire time the task was running. Removing this update helped improve stability not updating progress frequently enough ( see https://developer.apple.com/forums/thread/809182?page=1#868247022) My feature request is, would it be possible to get a reason the task was expired in task.expirationHandler? That would be helpful for both the user and for debugging why the task was expired. Thanks!

I posted here https://developer.apple.com/forums/thread/805554?page=1#867766022 but posting again for visibility (and let me know how I can file a bug) There was a response in that thread that said you could use the childProgress system to help updating progresses to keep the backgroundTask alive. What I've found is that using childProgresses results in more terminations than if you just updated the progress directly. Here is my setups to test this A BGContinuedProcessingTask that uses URLSessions to upload, and registers the task.progress with the Urlsession Progress Same, but the task.progress gets updated via a UrlSession Callback The second is MUCH more stable out in the field in cellular settings, the first fails extremely frequently. My suspicion is that in the documentation here https://developer.apple.com/documentation/foundation/progress#Reporting-Progress-for-Multiple-Operations it explicitly states The completedUnitCount property for a containing progress object only updates when the suboperation is 100% complete. The fractionCompleted property for a containing progress object updates continuously as work progresses for all suboperations. I wonder if BGContinuedProcessingTask is only looking at completedUnitCount for progress, and not fractionCompleted? In either case, I would love to use the childProgresses because there are bugs with retries by updating the progress manually, so would love some help resolving this, Thanks!

Testing Environment: iOS: 26.0 Beta 7 Xcode: Beta 6 Description: We are implementing the new BGContinuedProcessingTask API introduced in iOS 26. We have followed the official documentation and WWDC session guidance to configure our project. The Background Modes (processing) and Background GPU Access capabilities have been added in Xcode. The com.apple.developer.background-tasks.continued-processing.gpu entitlement is present and set to in the .entitlements file. The provisioning profile details viewed within Xcode explicitly show that the "Background GPU Access" capability and the corresponding entitlement are included. Despite this correct configuration, when running the app on supported hardware (iPhone 16 Pro), a call to BGTaskScheduler.supportedResources.contains(.gpu) consistently returns false. This prevents us from setting request.requiredResources = .gpu. As a result, when the BGContinuedProcessingTask starts without the GPU resource flag, our internal Metal-based exporter attempts to access the GPU and is terminated by the system, throwing an IOGPUMetalError: Insufficient Permission (to submit GPU work from background). We have performed extensive debugging, including a full reset of the provisioning profile (removing/re-adding capabilities, toggling automatic signing, cleaning build folders, and reinstalling the app), but the issue persists. This strongly suggests a bug in the iOS 26 beta where the runtime is failing to correctly validate a valid entitlement. Additionally, we've observed inconsistent behavior across devices. On an A16-based iPad, the task submits successfully (BGTaskScheduler.submit does not throw an error), but the launch handler is never invoked by the system. On the iPhone 16 Pro, the handler is invoked, but we encounter the supportedResources issue described above. This leads us to ask for clarification on the exact hardware requirements for this feature. We hypothesize that it may be limited to devices that support Apple Intelligence (A17 Pro and newer). Could you please confirm this and provide official documentation on the device support criteria? Steps to Reproduce: Create a new Xcode project. In Signing & Capabilities, add "Background Modes" (with "Background processing" checked) and "Background GPU Access". Add a permitted identifier (e.g., "com.company.test.*") to BGTaskSchedulerPermittedIdentifiers in Info.plist. In application(_:didFinishLaunchingWithOptions:) or a ViewController's viewDidLoad, log the result of BGTaskScheduler.shared.supportedResources.contains(.gpu). Build and run on a physical, supported device (e.g., iPhone 16 Pro). Expected Results: The log should indicate that BGTaskScheduler.shared.supportedResources.contains(.gpu) returns true. Actual Results: The log shows that BGTaskScheduler.shared.supportedResources.contains(.gpu) returns false.

Hi everyone, I’m encountering an unexpected Keychain behavior in a production environment and would like to confirm whether this is expected or if I’m missing something. In my app, I store a deviceId in the Keychain based on the classic KeychainItemWrapper implementation. I extended it by explicitly setting: kSecAttrAccessible = kSecAttrAccessibleAfterFirstUnlock My understanding is that kSecAttrAccessibleAfterFirstUnlock should allow Keychain access while the app is running in the background, as long as the device has been unlocked at least once after reboot. However, after the app went live, I observed that when the app performs background execution (e.g., triggered by background tasks / silent push), Keychain read attempts intermittently fail with: errSecInteractionNotAllowed (-25308) This seems inconsistent with the documented behavior of kSecAttrAccessibleAfterFirstUnlock. Additional context: The issue never occurs in foreground. The issue does not appear on development devices. User devices are not freshly rebooted when this happens. The Keychain item is created successfully; only background reads fail. Setting the accessibility to kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly produces the same result. Questions: Under what circumstances can kSecAttrAccessibleAfterFirstUnlock still cause a -25308 error? Is there any known restriction when accessing Keychain while the app is running in background execution contexts? Could certain system states (Low Power Mode, Background App Refresh conditions, device lock state, etc.) cause Keychain reads to be blocked unexpectedly? Any insights or similar experiences would be greatly appreciated. Thank you!

I’m looking for an authoritative answer on how BGAppRefreshTask behaves after a user force-quits an app (swipes it away in the App Switcher). My app relies on early-morning background refresh to prepare and schedule notifications based on user-defined thresholds and weather forecasts. Behavior across devices seems inconsistent, however: sometimes a scheduled background refresh still runs, and other times it appears completely blocked. Apple’s documentation doesn’t clearly state what should happen, and developer discussions conflict. Could someone from Apple please clarify: Will a previously scheduled BGAppRefreshTask run after the user force-quits the app? If not, is there a recommended alternative for time-sensitive updates that must schedule user alerts? What is the expected system behavior regarding the predictability of background refresh after a force-quit? A definitive answer would help ensure the app aligns with intended system behavior. Thanks!

I've adopted the new BGContinuedProcessingTask in iOS 26, and it has mostly been working well in internal testing. However, in production I'm getting reports of the tasks failing when the app is put into the background. A bit of info on what I'm doing: I need to download a large amount of data (around 250 files) and process these files as they come down. The size of the files can vary: for some tasks each file might be around 10MB. For other tasks, the files might be 40MB. The processing is relatively lightweight, but the volume of data means the task can potentially take over an hour on slower internet connections (up to 10GB of data). I set the totalUnitCount based on the number of files to be downloaded, and I increment completedUnitCount each time a file is completed. After some experimentation, I've found that smaller tasks (e.g. 3GB, 10MB per file) seem to be okay, but larger tasks (e.g. 10GB, 40MB per file) seem to fail, usually just a few seconds after the task is backgrounded (and without even opening any other apps). I think I've even observed a case where the task expired while the app was foregrounded! I'm trying to understand what the rules are with BGContinuedProcessingTask and I can see at least four possibilities that might be relevant: Is it necessary to provide progress updates at some minimum rate? For my larger tasks, where each file is ~40MB, there might be 20 or 30 seconds between progress updates. Does this make it more likely that the task will be expired? For larger tasks, the total time to complete can be 60–90 mins on slower internet connections. Is there some maximum amount of time the task can run for? Does the system attempt some kind of estimate of the overall time to complete and expire the task on that basis? The processing on each file is relatively lightweight, so most of the time the async stream is awaiting the next file to come down. Does the OS monitor the intensity of workload and suspend the task if it appears to be idle? I've noticed that the task UI sometimes displays a message, something along the lines of "Do you want to continue this task?" with a "Continue" and "Stop" option. What happens if the user simply ignores or doesn't see this message? Even if I tap "Continue" the task still seems to fail sometimes. I've read the docs and watched the WWDC video, but there's not a whole lot of information on the specific issues I mention above. It would be great to get some clarity on this, and I'd also appreciate any advice on alternative ways I could approach my specific use case.

Hello, I'm trying to adopt the new BGContinuedProcessingTask API, but I'm having a little trouble imagining how the API authors intended it be used. I saw the WWDC talk, but it lacked higher-level details about how to integrate this API, and I can't find a sample project. I notice that we can list wildcard background task identifiers in our Info.plist files now, and it appears this is to be used with continued tasks - a user might start one video encoding, then while it is ongoing, enqueue another one from the same app, and these tasks would have identifiers such as "MyApp.VideoEncoding.ABCD" and "MyApp.VideoEncoding.EFGH" to distinguish them. When it comes to implementing this, is the expectation that we: a) Register a single handler for the wildcard pattern, which then figures out how to fulfil each request from the identifier of the passed-in task instance? Or b) Register a unique handler for each instance of the wildcard pattern? Since you can't unregister handlers, any resources captured by the handler would be leaked, so you'd need to make sure you only register immediately before submission - in other words register + submit should always be called as a pair. Of course, I'd like to design my application to use this API as the authors intended it be used, but I'm just not entirely sure what that is. When I try to register a single handler for a wildcard pattern, the system rejects it at runtime (while allowing registrations for each instance of the pattern, indicating that at least my Info.plist is configured correctly). That points towards option B. If it is option B, it's potentially worth calling that out in documentation - or even better, perhaps introduce a new call just for BGContinuedProcessingTask instead of the separate register + submit calls? Thanks for your insight. K Aside: Also, it would be really nice if the handler closure would be async. Currently if you need to await on something, you need to launch an unstructured Task, but that causes issues since BGContinuedProcessingTask is not Sendable, so you can't pass it in to that Task to do things like update the title or mark the BGTask as complete.