diff --git a/Signal/src/ViewControllers/DebugUI/DebugUIBackup.m b/Signal/src/ViewControllers/DebugUI/DebugUIBackup.m
index be3d5c5f6..bb2b99b42 100644
--- a/Signal/src/ViewControllers/DebugUI/DebugUIBackup.m
+++ b/Signal/src/ViewControllers/DebugUI/DebugUIBackup.m
@@ -81,6 +81,18 @@ NS_ASSUME_NONNULL_BEGIN
                                      actionBlock:^{
                                          [AppEnvironment.shared.backupLazyRestore runIfNecessary];
                                      }]];
+    [items addObject:[OWSTableItem itemWithTitle:@"Upload 100 CK records"
+                                     actionBlock:^{
+                                         [DebugUIBackup uploadCKBatch:100];
+                                     }]];
+    [items addObject:[OWSTableItem itemWithTitle:@"Upload 1,000 CK records"
+                                     actionBlock:^{
+                                         [DebugUIBackup uploadCKBatch:1000];
+                                     }]];
+    [items addObject:[OWSTableItem itemWithTitle:@"Upload 10,000 CK records"
+                                     actionBlock:^{
+                                         [DebugUIBackup uploadCKBatch:10000];
+                                     }]];
 
     return [OWSTableSection sectionWithTitle:self.name items:items];
 }
@@ -221,6 +233,26 @@ NS_ASSUME_NONNULL_BEGIN
     [self.backup logBackupMetadataCache:OWSPrimaryStorage.sharedManager.newDatabaseConnection];
 }
 
++ (void)uploadCKBatch:(NSUInteger)count
+{
+    NSMutableArray<CKRecord *> *records = [NSMutableArray new];
+    for (NSUInteger i = 0; i < count; i++) {
+        NSData *_Nullable data = [Randomness generateRandomBytes:32];
+        OWSAssertDebug(data);
+        NSString *filePath = [OWSFileSystem temporaryFilePathWithFileExtension:@"pdf"];
+        BOOL success = [data writeToFile:filePath atomically:YES];
+        OWSAssertDebug(success);
+
+        NSString *recipientId = self.tsAccountManager.localNumber;
+        NSString *recordName = [OWSBackupAPI recordNameForTestFileWithRecipientId:recipientId];
+        CKRecord *record = [OWSBackupAPI recordForFileUrl:[NSURL fileURLWithPath:filePath] recordName:recordName];
+        [records addObject:record];
+    }
+    [[OWSBackupAPI saveRecordsToCloudObjcWithRecords:records].thenInBackground(^{
+        OWSLogVerbose(@"success.");
+    }) retainUntilComplete];
+}
+
 @end
 
 NS_ASSUME_NONNULL_END
diff --git a/Signal/src/util/Backup/OWSBackupAPI.swift b/Signal/src/util/Backup/OWSBackupAPI.swift
index f2acd8dbc..27c6c640f 100644
--- a/Signal/src/util/Backup/OWSBackupAPI.swift
+++ b/Signal/src/util/Backup/OWSBackupAPI.swift
@@ -134,8 +134,23 @@ import PromiseKit
     }
 
     public class func saveRecordsToCloud(records: [CKRecord]) -> Promise<Void> {
-        return saveRecordsToCloud(records: records,
-                                  remainingRetries: maxRetries)
+
+        var remainder = records
+        var promise = Promise.value(())
+        // CloudKit's internal limit is 400, but I haven't found a constant for this.
+        let kMaxBatchSize = 100
+        while remainder.count > 0 {
+            let batch = Array(remainder[0..<kMaxBatchSize])
+            remainder = Array(remainder[kMaxBatchSize..<remainder.count])
+            promise = promise.then(on: DispatchQueue.global()) { _ in
+                return saveRecordsToCloud(records: batch,
+                                          remainingRetries: maxRetries)
+            }.then(on: DispatchQueue.global()) { _ -> Promise<Void> in
+                Logger.verbose("Saved batch: \(batch.count)")
+                return Promise.value(())
+            }
+        }
+        return promise
     }
 
     private class func saveRecordsToCloud(records: [CKRecord],
@@ -144,7 +159,7 @@ import PromiseKit
         let recordNames = records.map { (record) in
             return record.recordID.recordName
         }
-        Logger.verbose("recordNames \(recordNames)")
+        Logger.verbose("recordNames[\(recordNames.count)] \(recordNames[0..<10])...")
 
         return Promise { resolver in
             let saveOperation = CKModifyRecordsOperation(recordsToSave: records, recordIDsToDelete: nil)
@@ -173,7 +188,7 @@ import PromiseKit
 
                 let outcome = outcomeForCloudKitError(error: error,
                                                       remainingRetries: remainingRetries,
-                                                      label: "Save Record")
+                                                      label: "Save Records[\(recordNames.count)]")
                 switch outcome {
                 case .success:
                     resolver.fulfill(())