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.

Hi everyone, I’m currently implementing Live Activities in my music app to display real-time lyrics on the Lock Screen. The app works fully offline, so I’m not using push updates or push tokens. Instead, I’m updating the Live Activity locally as each new line of lyrics is played (essentially near real-time updates synced with the song). However, I’m running into an issue where the Live Activity UI is not updating reliably or frequently enough. Even though I’m calling the update method for each lyric line, the changes are either delayed or not reflected at all. Here’s some additional context: • The app runs fine in the background (verified via battery usage and playback behavior) • Live Activity is successfully created and initially displayed • Updates are triggered locally (no push notifications involved) • Updates are happening quite frequently (per lyric line) • No crashes or errors are observed My questions: 1. Is there a system-imposed throttling limit on how frequently Live Activities can be updated locally? 2. Are there recommended update intervals for smooth UI updates (e.g., for use cases like lyrics or timers)? 3. Does Live Activity deprioritize updates for offline apps or background execution? 4. Are there any additional configurations or capabilities required to ensure consistent updates? 5. Is using something like AsyncStream or other concurrency patterns helpful in this case? 6. Are there any undocumented limitations or best practices for high-frequency updates? 7. Is there any private or internal API used by Apple apps (like Music) that allows smoother real-time updates? My goal is to achieve smooth, near real-time lyric updates similar to Apple Music’s Now Playing experience. Any guidance, best practices, or clarification would be greatly appreciated. Thanks in advance!

I'm developing a lighting control app for iOS that receives Art-Net (UDP port 6454) and sACN (UDP port 5568) packets from a lighting console and relays commands to BLE wristbands with LEDs. This is used in live event production — the participant locks their phone while in a show and expects lighting control to continue uninterrupted. The problem UDP receive stops reliably ~30 seconds after the screen locks. I understand this is by design - iOS suspends apps in the background. However, I'm trying to understand if any supported path exists for this use case. What I've already tried UIRequiresPersistentWiFi = true - helps with Wi-Fi association but doesn't prevent app suspension Silent AVAudioEngine loop with UIBackgroundModes: audio - keeps the app alive, works in testing, but risks App Store rejection and feels like an abuse of the audio background mode NWListener (Network framework) on the UDP port - same suspension behaviour Socket rebind on applicationWillEnterForeground - recovers after resume but doesn't prevent dropout What I'm asking Is there any supported background mode or entitlement for sustained UDP receive in a professional/enterprise context? (Similar to how VoIP apps get the voip background mode for sustained network activity.) Is the silent audio workaround considered acceptable for App Store distribution in a professional tools context, or will it be rejected? Is NEAppProxyProvider or another Network Extension a viable path, and if so does it require a special entitlement? Test project I have a minimal Xcode project (~130 lines) demonstrating the issue — NWListener on port 6454, packet counter, staleness timer, and silent audio toggle. I can share the test code. STEPS TO REPRODUCE In Xcode (one-time setup): Select the UDPBackgroundTest target → Signing & Capabilities → set your Team Plug in your iPhone → select it as the run destination Build & run — confirm packets appear on screen when you run 'send_test_udp.py' Lock the phone and observe the dropout Test: Open the app and run 'python3 send_test_udp.py 192.168.0.XXX' The app counts up the packages, they match the python output. 1 packet per second. lock screen & and wait 10 seconds unlock phone an see the numbers are 10 packets off

I am using Significant Location Change (SLC) monitoring to relaunch my app after it has been terminated. I have implemented SLC in two separate apps installed on the same device, and I would like to understand how the system delivers SLC events in this scenario. Specifically: Will both apps receive the SLC event at the same time, or can there be differences in the timing of delivery? If there are differences, what factors influence when each app receives the event? What criteria or system conditions determine how and when SLC events are delivered to different apps on the same device? Any clarification on the event delivery behavior would be greatly appreciated.

I'm developing a PHBackgroundResourceUploadExtension and finding it difficult to debug because the system controls when the extension launches. Current experience: The extension starts at unpredictable times (anywhere from 1 minute to several hours after photos are added) By the time I attach the debugger, the upload may have already completed or failed Breakpoints in init() or early lifecycle methods are often missed Questions: Is there a way to force-launch the extension during development (similar to how we can manually trigger Background App Refresh in Xcode)? Are there any launch arguments or environment variables that put the extension in a debug/eager mode? I tried taking photos/videos, but this doesn't trigged app extension in all cases. Any tips for improving the debug cycle would be greatly appreciated. Environment: iOS 26, Xcode 18

We are developing a watchOS application that records long audio sessions and uploads them to our backend in chunks (~5 MB each) using pre-signed URLs and URLSession background upload. Current behavior: While audio recording is active, uploads continue successfully even when the app is in the background. Once the recording stops, if multiple chunks (e.g., 10+) are still pending, the remaining uploads do not proceed in the background and appear to be suspended. We attempted to use WKExtendedRuntimeSession (mindfulness type) to allow sufficient time to enqueue background upload tasks, but the session is invalidated when the app goes to the background (e.g., wrist down or app inactive), which prevents reliable scheduling of uploads. Additionally, we added the entitlement: com.apple.developer.extended-runtime-session (mindfulness) in the Watch app entitlements file, but Xcode automatic signing fails with: “Provisioning profile does not include the com.apple.developer.extended-runtime-session entitlement.” It appears that the provisioning profile is not being updated to include this entitlement. Our questions: Is WKExtendedRuntimeSession (mindfulness) expected to support scheduling background URLSession uploads after the app goes to background? How should we reliably complete pending background uploads on watchOS after a long recording session ends? Is there any additional entitlement or recommended approach for this use case? Why is the extended runtime entitlement not being applied to the provisioning profile despite being added in the entitlements file? We are aiming to follow Apple-recommended practices for long-running tasks and background uploads on watchOS. Any guidance would be greatly appreciated.

I'm implementing a PHBackgroundResourceUploadExtension to back up photos and videos from the user's library to our cloud storage service. Our existing upload infrastructure uses chunked uploads for large files (splitting videos into smaller byte ranges and uploading each chunk separately). This approach: Allows resumable uploads if interrupted Stays within server-side request size limits Provides granular progress tracking Looking at the PHAssetResourceUploadJobChangeRequest.createJob(destination:resource:) API, I don't see a way to specify byte ranges or create multiple jobs for chunks of the same resource. Questions: Does the system handle large files (1GB+) automatically under the hood, or is there a recommended maximum file size for a single upload job? Is there a supported pattern for chunked/resumable uploads, or should the destination URL endpoint handle the entire file in one request? If our server requires chunked uploads (e.g., BITS protocol with CreateSession → Fragment → CloseSession), is this extension the right mechanism, or should we use a different approach for large videos? Any guidance on best practices for large asset uploads would be greatly appreciated. Environment: iOS 26, Xcode 18

I am developing an app used by public safety agencies. Part of the app is used to determine live agency staffing using geofences. For example, a geofence exists around a station, and when a user enters or exits that geofence, the app updates the staffing count at that station in real time. The issue I am having is reliably detecting when a user enters or exits the geofence while the app is killed (meaning the user force quit the app from the app launcher). I understand that iOS can relaunch an app in the background if the system terminated the process using Region Monitoring, but I haven't gotten a clear answer about whether or how this is possible if the user kills (force quits) the app. Thank you in advance for your assistance.

The expirationHandler on BGProcessingTask is a () -> Void closure. It provides no information about why it was called. In my testing, all of the following trigger the same handler: Time expiration Resource pressure (CPU, memory, battery) Not reporting progress User tapping "Stop" on the Live Activity There is no way for the app to tell these apart. Questions: Q1. Is there an official, complete list of all conditions that trigger expirationHandler? The documentation only mentions "time expires." Q2. What is the specific time limit before timeout? If it varies by device state, what are the conditions? Q3. A way to distinguish the reason is needed. "User stop" and "system expiration" require completely different handling. Currently this is impossible. Environment: iOS 26, physical device

I'm implementing PHBackgroundResourceUploadExtension to back up photos and videos to our cloud storage service. During testing, I observed that iCloud-optimized photos (where the full-resolution original is stored in iCloud, not on device) do not upload. The upload job appears to silently skip these assets. Questions: Is this behavior intentional/documented? I couldn't find explicit mention of this limitation. If the device only has the optimized/thumbnail version locally, does the system: - Automatically download the full-resolution asset from iCloud before uploading? - Skip the asset entirely? - Return an error via PHAssetResourceUploadJobChangeRequest? For a complete backup solution, should we: - Pre-fetch full-resolution assets using PHAssetResourceManager.requestData(for:options:) before creating upload jobs? - Use a hybrid approach (this extension for local assets + separate logic for iCloud-only assets)? Environment: iOS 26, Xcode 18

We are using BGContinuedProcessingTask on iOS 26 for long-running background video compression and upload. This work usually takes about 30 minutes to 1 hour. In testing on physical devices, expirationHandler is invoked irregularly. In some cases, it seems like it is caused by total task duration, and in other cases, it seems related to system resource conditions such as CPU, memory, or battery. However, even after many experiments, we have not been able to find a clear or consistent pattern. The important problem for us is that we cannot tell why expirationHandler was called. From the app’s perspective, we need to handle the following cases differently: the user taps Stop in the Live Activity the system expires the task due to time expiration the task is terminated due to system resource pressure (CPU, memory, battery, etc.) other system-driven termination cases However, at the moment, it is difficult or practically impossible to distinguish these cases reliably. My questions are: In the context of BGContinuedProcessingTask, is it correct to think that expirationHandler may be triggered by reasons such as time expiration, system resource pressure, and user stop? If so, is there any official or supported way for the app to distinguish between these reasons? For long-running work such as video compression and upload, is it expected behavior that expirationHandler is invoked irregularly? If BGContinuedProcessingTask is not a stable approach for 30-minute to 1-hour background work, is there any other recommended or more reliable way to perform this kind of long-running background processing on iOS without unexpected interruption? Environment: iOS 26, physical device

We are using BGContinuedProcessingTask on iOS 26 for long-running background video compression and upload. This work usually takes about 30 minutes to 1 hour. In testing on physical devices, expirationHandler is invoked irregularly. In some cases, it seems like it is caused by total task duration, and in other cases, it seems related to system resource conditions such as CPU, memory, or battery. However, even after many experiments, we have not been able to find a clear or consistent pattern. The important problem for us is that we cannot tell why expirationHandler was called. From the app’s perspective, we need to handle the following cases differently: • the user taps Stop in the Live Activity • the system expires the task due to time expiration • the task is terminated due to system resource pressure (CPU, memory, battery, etc.) • other system-driven termination cases However, at the moment, it is difficult or practically impossible to distinguish these cases reliably. My questions are: 1. In the context of BGContinuedProcessingTask, is it correct to think that expirationHandler may be triggered by reasons such as time expiration, system resource pressure, and user stop? 2. If so, is there any official or supported way for the app to distinguish between these reasons? 3. For long-running work such as video compression and upload, is it expected behavior that expirationHandler is invoked irregularly? 4. If BGContinuedProcessingTask is not a stable approach for 30-minute to 1-hour background work, is there any other recommended or more reliable way to perform this kind of long-running background processing on iOS without unexpected interruption? Environment: iOS 26, physical device

The expirationHandler on BGProcessingTask is a () -> Void closure. It provides no information about why it was called. In my testing, all of the following trigger the same handler: Time expiration Resource pressure (CPU, memory, battery) Not reporting progress User tapping "Stop" on the Live Activity There is no way for the app to tell these apart. Questions: Q1. Is there an official, complete list of all conditions that trigger expirationHandler? The documentation only mentions "time expires." Q2. What is the specific time limit before timeout? If it varies by device state, what are the conditions? Q3. A way to distinguish the reason is needed. "User stop" and "system expiration" require completely different handling. Currently this is impossible. Environment: iOS 26, physical device

Hi, I am trying to implement a PHBackgroundResourceUploadExtension to upload backup media files to an external cloud service based on these docs: https://developer.apple.com/documentation/PhotoKit/uploading-asset-resources-in-the-background#Acknowledge-completed-jobs Creating jobs and actual uploading is working as expected, but the problem I have is in the acknowledgeCompletedJobs() function. When trying to access a job's resource, the resource is nil and thus has empty assetLocalIdentifier and originalFilename. Did anybody successfully implement this extension or knows, why this would happen? Because the resource of an acknowledgable job is empty, I can not match it back to my processed assets.

Hi, I am trying to implement a PHBackgroundResourceUploadExtension to upload backup media files to an external cloud service based on these docs: https://developer.apple.com/documentation/PhotoKit/uploading-asset-resources-in-the-background#Acknowledge-completed-jobs Creating jobs and actual uploading is working as expected, but the problem I have is in the acknowledgeCompletedJobs() function. When in this function, I am trying to access a job's resource. The resource is nil and thus has empty assetLocalIdentifier and originalFilename. Did anybody successfully implement this extension or knows, why this would happen? Because the resource of an acknowledgable job is empty, I can not match it back to my processed assets.

We are developing a video processing app that applies CIFilter chains to video frames. To not force the user to keep the app foregrounded, we were happy to see the introduction of BGContinuedProcessingTask to continue processing when backgrounded. With iOS 26, I was excited to see the com.apple.developer.background-tasks.continued-processing.gpu entitlement, which should allow GPU access in the background. Even the article in the documentation provides "exporting video in a film-editing app" or "applying visual filters (HDR, etc) or compressing images for social media posts" as use cases. However, when I check BGTaskScheduler.shared.supportedResources.contains(.gpu) at runtime, it returns false on every iPhone I've tested (including iPhone 15 Pro and iPhone 16 Pro). From forum responses I've seen, it sounds like background GPU access is currently limited to iPad only. If that's the case, I have a few questions: Is this an intentional, permanent limitation — or is iPhone support planned for a future iOS release? What is the recommended approach for GPU-dependent background work on iPhone? My custom CIKernels are written in Metal (as Apple recommends since CIKL is deprecated), but Metal CIKernels cannot fall back to CPU rendering. This creates a situation where Apple's own deprecation guidance (migrate to Metal) conflicts with background processing realities (no GPU on iPhone). Should developers maintain deprecated CIKL kernel versions alongside Metal kernels purely as a CPU fallback for background execution? That feels like it defeats the purpose of the migration. It seems like a gap in the platform: the API exists, the entitlement exists, but the hardware support isn't there for the most common device category. Any clarity on Apple's direction here would be very helpful.

Hello, We are facing an issue with performing a DTLS handshake when our iOS application is in the background. Our app (Vocera Collaboration Suite – VCS) uses secure DTLS-encrypted communication for incoming VoIP calls. Problem Summary: When the app is in the background and a VoIP PushKit notification arrives, we attempt to establish a DTLS handshake over our existing socket. However, the handshake consistently fails unless the app is already in the foreground. Once the app is foregrounded, the same DTLS handshake logic succeeds immediately. Key Questions: Is performing a DTLS handshake while the app is in the background technically supported by iOS? Or is this an OS-level limitation by design? If not supported, what is the Apple-recommended alternative to establish secure DTLS communication for VoIP flows without bringing the app to the foreground? Any guidance or clarification from Apple engineers or anyone who has solved a similar problem would be greatly appreciated. Thank you.

Hello, I am using CLLocationManager to monitor multiple CLBeaconRegion instances (up to 20). When the app is terminated by the system (not force-quit) and a region enter event occurs, the app is relaunched in the background. I have two questions: What is the expected execution time window after relaunch before the app is suspended again? Is it supported to start short CoreBluetooth operations (e.g., scanning or connecting briefly) within this window? I understand that force-quitting the app disables background relaunch, so this question applies only to system-terminated apps.

Hi, I've now identified a few areas when BGContinuedProcessingTask gets expired by the system no progress for ~30 seconds high CPU usage high temperature Some of these I can preempt and expire preemptively and handle the notification, others I cannot and just need to let the failure bubble up. When the failure does bubble up, I'd like to update the title and subtitle. I'm able to update the title, but the subtitle is fixed at "Task Failed" Is there any workaround? Or shall I file a bug here?

Hi Everyone 🙌 Who knows, additional content that downloads in install time are summarized to total app size in App Store page ? If yes, additional size going to WiFi/Cell download recommendations ? And what the limit ? Will be appreciate of all information, maybe someone using Background Asset extension :pray:

I am implementing BLE scanning and connection using CoreBluetooth in a Flutter application with native iOS Swift code. BLE scanning and connection work correctly in the foreground and for a short time after the app is sent to the background. However, after some time in the background, BLE scanning stops and the device is no longer discovered. The app appears to be suspended by iOS. Key Observation: When location services are actively in use (navigation arrow visible in the iOS status bar), BLE scanning and reconnection work reliably in the background. When location services are not actively running, BLE scanning stops in the background even though the app has “Always Allow” location permission. Expected Result BLE scanning and connection should continue to function in the background using the Bluetooth LE background mode, without relying on active location updates. Actual Result BLE scanning starts successfully App enters background After some time, scanning stops Device is no longer discovered BLE works again only if location services are actively running BLE Connection Behavior One-time scan connects successfully to a BLE medical device App is sent to background Existing connection does not disconnect However, new scans or reconnections fail once the app is suspended Relevant Native iOS Code (AppDelegate) import Flutter import UIKit import CoreBluetooth @main @objc class AppDelegate: FlutterAppDelegate { private var backgroundTaskID: UIBackgroundTaskIdentifier = .invalid override func application( _ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]? ) -> Bool { GeneratedPluginRegistrant.register(with: self) if let identifiers = launchOptions?[UIApplication.LaunchOptionsKey.bluetoothCentrals] as? [String] { print("App relaunched for BLE state restoration: \(identifiers)") } NotificationCenter.default.addObserver( self, selector: #selector(appDidEnterBackground), name: UIApplication.didEnterBackgroundNotification, object: nil ) return super.application(application, didFinishLaunchingWithOptions: launchOptions) } @objc private func appDidEnterBackground() { backgroundTaskID = UIApplication.shared.beginBackgroundTask { self.endBackgroundTask() } } private func endBackgroundTask() { if backgroundTaskID != .invalid { UIApplication.shared.endBackgroundTask(backgroundTaskID) backgroundTaskID = .invalid } } } Questions for DTS: Is it expected behavior that CoreBluetooth background scanning effectively stops once the app is suspended, even when the Bluetooth LE background mode is enabled? Why does BLE background scanning appear to work reliably only when location services are actively running? Is iOS internally associating BLE background execution with active location updates? For continuous BLE reconnection (medical device use case), is the recommended approach to rely solely on CoreBluetooth state restoration instead of continuous background scanning? Is it considered best practice to avoid long-running BLE scans in the background and instead wait for system-delivered BLE events? Additional Notes Issue is reproducible on real devices Not using private APIs or unsupported background execution methods Objective is to follow Apple-recommended, App Store–compliant behavior