diff --git a/README.md b/README.md
index 0453b7b4..60788233 100644
--- a/README.md
+++ b/README.md
@@ -79,6 +79,11 @@ The preferences window is used to point to a local running instance, a remote in
 It is possible to run your own instance and point to it for advanced/development purposes.
 You should only change the settings if you know what you are doing.
 
+The Syncthing process quality of service can be set to Normal, Utility, or Background in the
+preferences window. Background is the default for compatibility and reduces the process impact on
+foreground applications, but it can make large folder scans take longer. Changing this setting
+restarts the managed Syncthing process.
+
 Setting extra Syncthing command line parameters is a hidden feature. You need to write these using
 the application defaults configuration. The only current limitation the parameters cannot contain spaces!.
 In the example below the audit log is enabled:
diff --git a/syncthing/Base.lproj/STPreferencesWindowGeneralView.xib b/syncthing/Base.lproj/STPreferencesWindowGeneralView.xib
index 3e455a2f..391adfbb 100644
--- a/syncthing/Base.lproj/STPreferencesWindowGeneralView.xib
+++ b/syncthing/Base.lproj/STPreferencesWindowGeneralView.xib
@@ -8,6 +8,9 @@
     <objects>
         <customObject id="-2" userLabel="File's Owner" customClass="STPreferencesGeneralViewController">
             <connections>
+                <outlet property="DaemonQoSBackground" destination="QoS-Bg-A01" id="QoS-Bg-O01"/>
+                <outlet property="DaemonQoSDefault" destination="QoS-Df-A01" id="QoS-Df-O01"/>
+                <outlet property="DaemonQoSUtility" destination="QoS-Ut-A01" id="QoS-Ut-O01"/>
                 <outlet property="ProxyURL" destination="X8z-m3-H7F" id="Fn0-3o-LfW"/>
                 <outlet property="StartAtLogin" destination="tYl-sb-Hga" id="nUj-DN-esv"/>
                 <outlet property="Syncthing_ApiKey" destination="B0w-Uv-22O" id="DX5-97-308"/>
@@ -20,7 +23,7 @@
         <customObject id="-1" userLabel="First Responder" customClass="FirstResponder"/>
         <customObject id="-3" userLabel="Application" customClass="NSObject"/>
         <customView translatesAutoresizingMaskIntoConstraints="NO" id="Hz6-mo-xeY">
-            <rect key="frame" x="0.0" y="0.0" width="457" height="248"/>
+            <rect key="frame" x="0.0" y="0.0" width="457" height="303"/>
             <subviews>
                 <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="SPp-6x-JiZ">
                     <rect key="frame" x="18" y="121" width="49" height="16"/>
@@ -120,6 +123,52 @@
                         <color key="backgroundColor" name="controlColor" catalog="System" colorSpace="catalog"/>
                     </textFieldCell>
                 </textField>
+                <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="QoS-Lb-A01">
+                    <rect key="frame" x="18" y="56" width="49" height="16"/>
+                    <textFieldCell key="cell" scrollable="YES" lineBreakMode="clipping" sendsActionOnEndEditing="YES" alignment="right" title="Priority" id="QoS-Lb-C01">
+                        <font key="font" metaFont="system"/>
+                        <color key="textColor" name="labelColor" catalog="System" colorSpace="catalog"/>
+                        <color key="backgroundColor" name="controlColor" catalog="System" colorSpace="catalog"/>
+                    </textFieldCell>
+                </textField>
+                <button translatesAutoresizingMaskIntoConstraints="NO" id="QoS-Df-A01">
+                    <rect key="frame" x="71" y="56" width="75" height="18"/>
+                    <buttonCell key="cell" type="radio" title="Normal" bezelStyle="regularSquare" imagePosition="left" inset="2" id="QoS-Df-C01">
+                        <behavior key="behavior" changeContents="YES" doesNotDimImage="YES" lightByContents="YES"/>
+                        <font key="font" metaFont="system"/>
+                    </buttonCell>
+                    <connections>
+                        <action selector="clickedDaemonQualityOfService:" target="-2" id="QoS-Df-X01"/>
+                    </connections>
+                </button>
+                <button tag="1" translatesAutoresizingMaskIntoConstraints="NO" id="QoS-Ut-A01">
+                    <rect key="frame" x="158" y="56" width="75" height="18"/>
+                    <buttonCell key="cell" type="radio" title="Utility" bezelStyle="regularSquare" imagePosition="left" inset="2" id="QoS-Ut-C01">
+                        <behavior key="behavior" changeContents="YES" doesNotDimImage="YES" lightByContents="YES"/>
+                        <font key="font" metaFont="system"/>
+                    </buttonCell>
+                    <connections>
+                        <action selector="clickedDaemonQualityOfService:" target="-2" id="QoS-Ut-X01"/>
+                    </connections>
+                </button>
+                <button tag="2" translatesAutoresizingMaskIntoConstraints="NO" id="QoS-Bg-A01">
+                    <rect key="frame" x="245" y="56" width="110" height="18"/>
+                    <buttonCell key="cell" type="radio" title="Background" bezelStyle="regularSquare" imagePosition="left" inset="2" id="QoS-Bg-C01">
+                        <behavior key="behavior" changeContents="YES" doesNotDimImage="YES" lightByContents="YES"/>
+                        <font key="font" metaFont="system"/>
+                    </buttonCell>
+                    <connections>
+                        <action selector="clickedDaemonQualityOfService:" target="-2" id="QoS-Bg-X01"/>
+                    </connections>
+                </button>
+                <textField horizontalHuggingPriority="251" verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="QoS-Hp-A01">
+                    <rect key="frame" x="73" y="17" width="364" height="34"/>
+                    <textFieldCell key="cell" lineBreakMode="byWordWrapping" sendsActionOnEndEditing="YES" title="Background saves energy but can make large scans slower. Changes restart Syncthing automatically." id="QoS-Hp-C01">
+                        <font key="font" metaFont="smallSystem"/>
+                        <color key="textColor" name="secondaryLabelColor" catalog="System" colorSpace="catalog"/>
+                        <color key="backgroundColor" name="controlColor" catalog="System" colorSpace="catalog"/>
+                    </textFieldCell>
+                </textField>
                 <button translatesAutoresizingMaskIntoConstraints="NO" id="aC0-rw-4G1">
                     <rect key="frame" x="71" y="117" width="134" height="18"/>
                     <buttonCell key="cell" type="check" title="Show in menu bar" bezelStyle="regularSquare" imagePosition="left" inset="2" id="nB8-OA-X1F">
@@ -185,11 +234,22 @@
                 <constraint firstAttribute="trailing" secondItem="B0w-Uv-22O" secondAttribute="trailing" constant="20" symbolic="YES" id="lWZ-ef-Ed2"/>
                 <constraint firstItem="B0w-Uv-22O" firstAttribute="top" secondItem="kCf-gA-qTB" secondAttribute="bottom" constant="10" symbolic="YES" id="mg0-kD-bnu"/>
                 <constraint firstItem="N0T-mL-rWn" firstAttribute="leading" secondItem="kCf-gA-qTB" secondAttribute="leading" id="nfs-eY-QdR"/>
+                <constraint firstItem="QoS-Lb-A01" firstAttribute="leading" secondItem="Hz6-mo-xeY" secondAttribute="leading" constant="20" symbolic="YES" id="QoS-Lb-K01"/>
+                <constraint firstItem="QoS-Lb-A01" firstAttribute="firstBaseline" secondItem="QoS-Df-A01" secondAttribute="firstBaseline" id="QoS-Lb-K02"/>
+                <constraint firstItem="QoS-Df-A01" firstAttribute="leading" secondItem="kCf-gA-qTB" secondAttribute="leading" id="QoS-Df-K01"/>
+                <constraint firstItem="QoS-Df-A01" firstAttribute="top" secondItem="N0T-mL-rWn" secondAttribute="bottom" constant="14" id="QoS-Df-K02"/>
+                <constraint firstItem="QoS-Ut-A01" firstAttribute="leading" secondItem="QoS-Df-A01" secondAttribute="trailing" constant="12" id="QoS-Ut-K01"/>
+                <constraint firstItem="QoS-Ut-A01" firstAttribute="firstBaseline" secondItem="QoS-Df-A01" secondAttribute="firstBaseline" id="QoS-Ut-K02"/>
+                <constraint firstItem="QoS-Bg-A01" firstAttribute="leading" secondItem="QoS-Ut-A01" secondAttribute="trailing" constant="12" id="QoS-Bg-K01"/>
+                <constraint firstItem="QoS-Bg-A01" firstAttribute="firstBaseline" secondItem="QoS-Df-A01" secondAttribute="firstBaseline" id="QoS-Bg-K02"/>
+                <constraint firstItem="QoS-Hp-A01" firstAttribute="leading" secondItem="kCf-gA-qTB" secondAttribute="leading" id="QoS-Hp-K01"/>
+                <constraint firstAttribute="trailing" secondItem="QoS-Hp-A01" secondAttribute="trailing" constant="20" symbolic="YES" id="QoS-Hp-K02"/>
+                <constraint firstItem="QoS-Hp-A01" firstAttribute="top" secondItem="QoS-Df-A01" secondAttribute="bottom" constant="6" id="QoS-Hp-K03"/>
                 <constraint firstAttribute="trailing" secondItem="N0T-mL-rWn" secondAttribute="trailing" constant="20" symbolic="YES" id="uZa-6N-IxU"/>
                 <constraint firstItem="N0T-mL-rWn" firstAttribute="top" secondItem="X8z-m3-H7F" secondAttribute="bottom" constant="8" symbolic="YES" id="upT-DS-vcQ"/>
                 <constraint firstItem="bgQ-af-R3Y" firstAttribute="firstBaseline" secondItem="kCf-gA-qTB" secondAttribute="firstBaseline" id="r3e-1n-EcE"/>
                 <constraint firstItem="tYl-sb-Hga" firstAttribute="leading" secondItem="kCf-gA-qTB" secondAttribute="leading" id="tVU-d6-WRW"/>
-                <constraint firstItem="tYl-sb-Hga" firstAttribute="top" secondItem="N0T-mL-rWn" secondAttribute="bottom" constant="12" id="uMJ-HV-WQG"/>
+                <constraint firstItem="tYl-sb-Hga" firstAttribute="top" secondItem="QoS-Hp-A01" secondAttribute="bottom" constant="12" id="uMJ-HV-WQG"/>
                 <constraint firstItem="9Rm-9W-VFZ" firstAttribute="leading" relation="greaterThanOrEqual" secondItem="NQY-Se-yQr" secondAttribute="trailing" constant="7" id="ucj-yE-cmL"/>
                 <constraint firstItem="SPp-6x-JiZ" firstAttribute="leading" secondItem="Hz6-mo-xeY" secondAttribute="leading" constant="20" symbolic="YES" id="udY-T2-UbN"/>
                 <constraint firstItem="kCf-gA-qTB" firstAttribute="top" secondItem="Hz6-mo-xeY" secondAttribute="top" constant="20" symbolic="YES" id="xAJ-NF-i59"/>
diff --git a/syncthing/DaemonProcess.swift b/syncthing/DaemonProcess.swift
index d810111f..d440e58b 100644
--- a/syncthing/DaemonProcess.swift
+++ b/syncthing/DaemonProcess.swift
@@ -72,6 +72,19 @@ let MaxKeepLogLines = 200
         return environment
     }
 
+    private func launchQualityOfService() -> QualityOfService {
+        let value = UserDefaults.standard.string(forKey: "DaemonQualityOfService") ?? "background"
+
+        switch value {
+        case "default":
+            return .default
+        case "utility":
+            return .utility
+        default:
+            return .background
+        }
+    }
+
     @objc func launch() {
         queue.async {
             self.launchSync()
@@ -105,7 +118,7 @@ let MaxKeepLogLines = 200
         p.standardOutput = pipeIntoLineBuffer()
         p.standardError = pipeIntoLineBuffer()
         p.terminationHandler = { p in self.queue.async { self.didTerminate(p) } }
-        p.qualityOfService = QualityOfService.background
+        p.qualityOfService = launchQualityOfService()
         p.launch()
 
         DispatchQueue.main.async {
diff --git a/syncthing/STPreferencesWindowGeneralViewController.h b/syncthing/STPreferencesWindowGeneralViewController.h
index f9e48f7e..3842e668 100644
--- a/syncthing/STPreferencesWindowGeneralViewController.h
+++ b/syncthing/STPreferencesWindowGeneralViewController.h
@@ -16,6 +16,9 @@
 @property (weak) IBOutlet NSTextField *Syncthing_ApiKey;
 @property (weak) IBOutlet NSButton *StartAtLogin;
 @property (weak) IBOutlet NSButton *buttonTest;
+@property (weak) IBOutlet NSButton *DaemonQoSDefault;
+@property (weak) IBOutlet NSButton *DaemonQoSUtility;
+@property (weak) IBOutlet NSButton *DaemonQoSBackground;
 
 extern NSNotificationName const STDaemonNeedsRestartNotification;
 
diff --git a/syncthing/STPreferencesWindowGeneralViewController.m b/syncthing/STPreferencesWindowGeneralViewController.m
index 65bfe413..f10d8e12 100644
--- a/syncthing/STPreferencesWindowGeneralViewController.m
+++ b/syncthing/STPreferencesWindowGeneralViewController.m
@@ -12,6 +12,17 @@
 
 NSNotificationName const STDaemonNeedsRestartNotification = @"STDaemonNeedsRestartNotification";
 
+static NSString * const STDaemonQualityOfServiceKey = @"DaemonQualityOfService";
+static NSString * const STDaemonQualityOfServiceDefault = @"default";
+static NSString * const STDaemonQualityOfServiceUtility = @"utility";
+static NSString * const STDaemonQualityOfServiceBackground = @"background";
+
+typedef NS_ENUM(NSInteger, STDaemonQualityOfServiceTag) {
+    STDaemonQualityOfServiceTagDefault = 0,
+    STDaemonQualityOfServiceTagUtility = 1,
+    STDaemonQualityOfServiceTagBackground = 2,
+};
+
 @interface STPreferencesWindowGeneralViewController ()
 
 @end
@@ -21,6 +32,7 @@ @implementation STPreferencesWindowGeneralViewController
 - (void) viewDidLoad {
     [super viewDidLoad];
     [self updateProxyControls];
+    [self updateDaemonQualityOfServiceControls];
     [self updateTestButton];
 }
 
@@ -70,6 +82,27 @@ - (IBAction)proxyUrlChanged:(id)sender {
     [self postDaemonRestartNotification];
 }
 
+- (IBAction)clickedDaemonQualityOfService:(NSButton *)sender {
+    NSString *qualityOfService = STDaemonQualityOfServiceBackground;
+
+    switch (sender.tag) {
+        case STDaemonQualityOfServiceTagDefault:
+            qualityOfService = STDaemonQualityOfServiceDefault;
+            break;
+        case STDaemonQualityOfServiceTagUtility:
+            qualityOfService = STDaemonQualityOfServiceUtility;
+            break;
+        case STDaemonQualityOfServiceTagBackground:
+            break;
+        default:
+            return;
+    }
+
+    [[NSUserDefaults standardUserDefaults] setObject:qualityOfService forKey:STDaemonQualityOfServiceKey];
+    [self updateDaemonQualityOfServiceControls];
+    [self postDaemonRestartNotification];
+}
+
 - (void)postDaemonRestartNotification {
     [[NSNotificationCenter defaultCenter] postNotificationName:STDaemonNeedsRestartNotification object:self];
 }
@@ -78,4 +111,23 @@ - (void)updateProxyControls {
     [self.ProxyURL setEnabled:(self.UseProxy.state == NSControlStateValueOn)];
 }
 
+- (void)updateDaemonQualityOfServiceControls {
+    NSString *qualityOfService = [[NSUserDefaults standardUserDefaults] stringForKey:STDaemonQualityOfServiceKey];
+    NSSet<NSString *> *validValues = [NSSet setWithObjects:
+        STDaemonQualityOfServiceDefault,
+        STDaemonQualityOfServiceUtility,
+        STDaemonQualityOfServiceBackground,
+        nil];
+    if (!qualityOfService || ![validValues containsObject:qualityOfService]) {
+        qualityOfService = STDaemonQualityOfServiceBackground;
+    }
+
+    self.DaemonQoSDefault.state = [qualityOfService isEqualToString:STDaemonQualityOfServiceDefault]
+        ? NSControlStateValueOn : NSControlStateValueOff;
+    self.DaemonQoSUtility.state = [qualityOfService isEqualToString:STDaemonQualityOfServiceUtility]
+        ? NSControlStateValueOn : NSControlStateValueOff;
+    self.DaemonQoSBackground.state = [qualityOfService isEqualToString:STDaemonQualityOfServiceBackground]
+        ? NSControlStateValueOn : NSControlStateValueOff;
+}
+
 @end
diff --git a/syncthing/en.lproj/STPreferencesWindowGeneralView.strings b/syncthing/en.lproj/STPreferencesWindowGeneralView.strings
index d66e96e6..5753622b 100644
--- a/syncthing/en.lproj/STPreferencesWindowGeneralView.strings
+++ b/syncthing/en.lproj/STPreferencesWindowGeneralView.strings
@@ -25,3 +25,18 @@
 
 /* Class = "NSButtonCell"; title = "Show in menu bar"; ObjectID = "nB8-OA-X1F"; */
 "nB8-OA-X1F.title" = "Show in menu bar";
+
+/* Class = "NSTextFieldCell"; title = "Priority"; ObjectID = "QoS-Lb-C01"; */
+"QoS-Lb-C01.title" = "Priority";
+
+/* Class = "NSButtonCell"; title = "Normal"; ObjectID = "QoS-Df-C01"; */
+"QoS-Df-C01.title" = "Normal";
+
+/* Class = "NSButtonCell"; title = "Utility"; ObjectID = "QoS-Ut-C01"; */
+"QoS-Ut-C01.title" = "Utility";
+
+/* Class = "NSButtonCell"; title = "Background"; ObjectID = "QoS-Bg-C01"; */
+"QoS-Bg-C01.title" = "Background";
+
+/* Class = "NSTextFieldCell"; title = "Background saves energy but can make large scans slower. Changes restart Syncthing automatically."; ObjectID = "QoS-Hp-C01"; */
+"QoS-Hp-C01.title" = "Background saves energy but can make large scans slower. Changes restart Syncthing automatically.";
diff --git a/syncthing/es.lproj/STPreferencesWindowGeneralView.strings b/syncthing/es.lproj/STPreferencesWindowGeneralView.strings
index 1a66efd2..261fb0e4 100644
--- a/syncthing/es.lproj/STPreferencesWindowGeneralView.strings
+++ b/syncthing/es.lproj/STPreferencesWindowGeneralView.strings
@@ -25,3 +25,18 @@
 
 /* Class = "NSButtonCell"; title = "Show in menu bar"; ObjectID = "nB8-OA-X1F"; */
 "nB8-OA-X1F.title" = "Mostrar en la barra de menú";
+
+/* Class = "NSTextFieldCell"; title = "Priority"; ObjectID = "QoS-Lb-C01"; */
+"QoS-Lb-C01.title" = "Prioridad";
+
+/* Class = "NSButtonCell"; title = "Normal"; ObjectID = "QoS-Df-C01"; */
+"QoS-Df-C01.title" = "Normal";
+
+/* Class = "NSButtonCell"; title = "Utility"; ObjectID = "QoS-Ut-C01"; */
+"QoS-Ut-C01.title" = "Utilidad";
+
+/* Class = "NSButtonCell"; title = "Background"; ObjectID = "QoS-Bg-C01"; */
+"QoS-Bg-C01.title" = "Segundo plano";
+
+/* Class = "NSTextFieldCell"; title = "Background saves energy but can make large scans slower. Changes restart Syncthing automatically."; ObjectID = "QoS-Hp-C01"; */
+"QoS-Hp-C01.title" = "Segundo plano ahorra energía, pero puede ralentizar los análisis grandes. Los cambios reinician Syncthing automáticamente.";