# Reducing your app’s disk usage Measure and minimize the space your app uses to store its files. ## Overview People use multiple apps on a device, to create and access important content. Minimize your app’s disk usage to make more space for a person’s content, and to allow someone to install more apps on their device. Store recoverable data in purgeable locations, so that the system can free up space when it needs to. ### Review your app’s disk usage To see the storage used by each app on your device, open Settings and choose General > Storage.  Tap on your app to see a breakdown of how the app’s bundle, documents, and data contribute to the overall disk usage. ### Gather metrics on disk usage Use to gather metrics on the number of files in your app’s container and the disk space they occupy. Observe the `metricReports` asynchronous sequence and read the file count and size values from the daily report: ```swift import MetricKit let manager = MetricManager() for await report in manager.metricReports { let entry = report.intervalEntries.fullDayEntry for value in entry.values { switch value { case let .totalFileSize(metric): // Analyze your app's disk usage. break case let .totalFileCount(metric): // Track the number of files in your app's container. break @unknown default: break } } } ``` ### Use purgeable folders for recoverable content When you download or otherwise generate content that your app can recover if it needs to, store that content in the or the . The system automatically deletes content in the `cachesDirectory` and `temporaryDirectory` — an operation known as *purging* — when it detects that disk space is low. ```swift let cacheDownloadTask = URLSession.shared.downloadTask(with: cacheURL) { fileURL, response, error // Check for download errors and handle them. guard let temporaryURL = fileURL else { return } do { let destinationURL = URL.cachesDirectory.appendingPathComponent(temporaryURL.lastPathComponent) try FileManager.default.moveItem(at: temporaryURL, to: destinationURL) } catch { // Handle the error. } } ``` ### Manage local copies of iCloud files When a person isn’t using the local copy of a file that’s stored in iCloud, call to remove the local copy while keeping the original on iCloud: ```swift func removeLocalDocument(at localURL: URL) throws { let resources = try localURL.resourceValues(forKeys: [.ubiquitousItemIsUploadedKey]) guard resources.ubiquitousItemIsUploaded == true else { return } FileManager.default.evictUbiquitousItem(at: localURL) } ``` You can subsequently retrieve the file from iCloud by calling : ```swift func fetchRemoteDocument(for localURL: URL) throws { let resources = try localURL.resourceValues(forKeys: [.ubiquitousItemIsUploadedKey]) guard resources.ubiquitousItemIsUploaded != true else { return } FileManager.default.startDownloadingUbiquitousItem(at: localURL) } ``` > Warning: > If you delete a file from iCloud by calling , the system deletes both the local and iCloud copy, and you can’t recover the file. ### Copy files by creating clones When you use to copy a file on an APFS volume, the system creates a *clone* of the file. The clone refers to the original file’s content, so it uses less space on disk than if you duplicate the file through other methods. MetricKit’s accounts for clones in its calculations of the disk space used by your app. For more information, see . --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)