diff --git a/lib/alarm/types/alarm.dart b/lib/alarm/types/alarm.dart
index bd23d5df..d4f004e3 100644
--- a/lib/alarm/types/alarm.dart
+++ b/lib/alarm/types/alarm.dart
@@ -450,4 +450,8 @@ class Alarm extends CustomizableListItem {
         'settings': _settings.valueToJson(),
         'skippedTime': _skippedTime?.millisecondsSinceEpoch,
       };
+
+  bool isEqualTo(Alarm other) {
+    return _time == other._time && _settings.isEqualTo(other._settings);
+  }
 }
diff --git a/lib/common/types/tag.dart b/lib/common/types/tag.dart
index d665fbfe..0e1fae0e 100644
--- a/lib/common/types/tag.dart
+++ b/lib/common/types/tag.dart
@@ -49,4 +49,10 @@ class Tag extends ListItem {
     description = other.description;
     color = other.color;
   }
+
+  bool isEqualTo(Tag other) {
+    return name == other.name &&
+        description == other.description &&
+        color == other.color;
+  }
 }
diff --git a/lib/common/types/time.dart b/lib/common/types/time.dart
index 4cd27f5c..74f29bce 100644
--- a/lib/common/types/time.dart
+++ b/lib/common/types/time.dart
@@ -69,4 +69,18 @@ class Time extends JsonSerializable {
       return time >= startTime || time <= endTime;
     }
   }
+
+  @override
+  bool operator ==(Object other) {
+    if (other is Time) {
+      return hour == other.hour &&
+          minute == other.minute &&
+          second == other.second;
+    }
+    return false;
+  }
+
+  @override
+  int get hashCode => Object.hash(hour, minute, second);
+
 }
diff --git a/lib/settings/data/backup_options.dart b/lib/settings/data/backup_options.dart
index c6fc30f3..01c76d5a 100644
--- a/lib/settings/data/backup_options.dart
+++ b/lib/settings/data/backup_options.dart
@@ -4,6 +4,7 @@ import 'package:clock_app/alarm/logic/update_alarms.dart';
 import 'package:clock_app/alarm/types/alarm.dart';
 import 'package:clock_app/app.dart';
 import 'package:clock_app/clock/types/city.dart';
+import 'package:clock_app/common/types/tag.dart';
 import 'package:clock_app/common/utils/json_serialize.dart';
 import 'package:clock_app/common/utils/list_storage.dart';
 import 'package:clock_app/settings/data/settings_schema.dart';
@@ -27,11 +28,13 @@ final backupOptions = [
       return await loadTextFile("tags");
     },
     decode: (context, value) async {
-      await saveList<TimerPreset>("tags", [
-        ...listFromString<TimerPreset>(value)
-            .map((tag) => TimerPreset.from(tag)),
-        ...await loadList<TimerPreset>("tags")
-      ]);
+      final existingItems = await loadList<Tag>("tags");
+      final itemsToAdd = listFromString<Tag>(value)
+          .where((tag) =>
+              !existingItems.any((existingTag) => existingTag.isEqualTo(tag)))
+          .map((tag) => Tag.from(tag));
+
+      await saveList<Tag>("tags", [...itemsToAdd, ...existingItems]);
     },
   ),
   BackupOption(
@@ -45,10 +48,15 @@ final backupOptions = [
       return listToString(customColorSchemes);
     },
     decode: (context, value) async {
+      final existingItems = await loadList<ColorSchemeData>("color_schemes");
+      final itemsToAdd = listFromString<ColorSchemeData>(value)
+          .where((colorScheme) => !existingItems.any((existingColorScheme) =>
+              existingColorScheme.isEqualTo(colorScheme)))
+          .map((scheme) => ColorSchemeData.from(scheme));
+
       await saveList<ColorSchemeData>("color_schemes", [
-        ...listFromString<ColorSchemeData>(value)
-            .map((scheme) => ColorSchemeData.from(scheme)),
-        ...await loadList<ColorSchemeData>("color_schemes")
+        ...itemsToAdd,
+        ...existingItems,
       ]);
       if (context.mounted) App.refreshTheme(context);
     },
@@ -63,11 +71,13 @@ final backupOptions = [
       return listToString(customThemes);
     },
     decode: (context, value) async {
-      await saveList<StyleTheme>("style_themes", [
-        ...listFromString<StyleTheme>(value)
-            .map((theme) => StyleTheme.from(theme)),
-        ...await loadList<StyleTheme>("style_themes")
-      ]);
+      final existingItems = await loadList<StyleTheme>("style_themes");
+      final itemsToAdd = listFromString<StyleTheme>(value)
+          .where((theme) => !existingItems
+              .any((existingTheme) => existingTheme.isEqualTo(theme)))
+          .map((theme) => StyleTheme.from(theme));
+      await saveList<StyleTheme>(
+          "style_themes", [...itemsToAdd, ...existingItems]);
       if (context.mounted) App.refreshTheme(context);
     },
   ),
@@ -94,10 +104,12 @@ final backupOptions = [
       return await loadTextFile("alarms");
     },
     decode: (context, value) async {
-      await saveList<Alarm>("alarms", [
-        ...listFromString<Alarm>(value).map((alarm) => Alarm.fromAlarm(alarm)),
-        ...await loadList<Alarm>("alarms")
-      ]);
+      final existingItems = await loadList<Alarm>("alarms");
+      final itemsToAdd = listFromString<Alarm>(value)
+          .where((alarm) => !existingItems
+              .any((existingAlarm) => existingAlarm.isEqualTo(alarm)))
+          .map((alarm) => Alarm.fromAlarm(alarm));
+      await saveList<Alarm>("alarms", [...itemsToAdd, ...existingItems]);
       await updateAlarms("Updated alarms on importing backup");
     },
   ),
@@ -108,11 +120,12 @@ final backupOptions = [
       return await loadTextFile("timers");
     },
     decode: (context, value) async {
-      await saveList<ClockTimer>("timers", [
-        ...listFromString<ClockTimer>(value)
-            .map((timer) => ClockTimer.from(timer)),
-        ...await loadList<ClockTimer>("timers")
-      ]);
+      final existingItems = await loadList<ClockTimer>("timers");
+      final itemsToAdd = listFromString<ClockTimer>(value)
+          .where((timer) => !existingItems
+              .any((existingTimer) => existingTimer.isEqualTo(timer)))
+          .map((timer) => ClockTimer.from(timer));
+      await saveList<ClockTimer>("timers", [...itemsToAdd, ...existingItems]);
       await updateTimers("Updated timers on importing backup");
     },
   ),
@@ -151,11 +164,14 @@ final backupOptions = [
       return await loadTextFile("timer_presets");
     },
     decode: (context, value) async {
-      await saveList<TimerPreset>("timer_presets", [
-        ...listFromString<TimerPreset>(value)
-            .map((preset) => TimerPreset.from(preset)),
-        ...await loadList<TimerPreset>("timer_presets")
-      ]);
+      final existingItems = await loadList<TimerPreset>("timer_presets");
+      final itemsToAdd = listFromString<TimerPreset>(value)
+          .where((preset) => !existingItems
+              .any((existingPreset) => existingPreset.isEqualTo(preset)))
+          .map((preset) => TimerPreset.from(preset));
+
+      await saveList<TimerPreset>(
+          "timer_presets", [...itemsToAdd, ...existingItems]);
     },
   ),
 ];
diff --git a/lib/settings/types/setting.dart b/lib/settings/types/setting.dart
index af975507..1acbdae7 100644
--- a/lib/settings/types/setting.dart
+++ b/lib/settings/types/setting.dart
@@ -68,7 +68,8 @@ abstract class Setting<T> extends SettingItem {
   }
 }
 
-class CustomizableListSetting<T extends CustomizableListItem> extends Setting<List<T>> {
+class CustomizableListSetting<T extends CustomizableListItem>
+    extends Setting<List<T>> {
   List<T> possibleItems;
   Widget Function(T item, [VoidCallback?, VoidCallback?]) cardBuilder;
   Widget Function(T item) addCardBuilder;
@@ -198,8 +199,6 @@ class ListSetting<T extends ListItem> extends Setting<List<T>> {
     );
   }
 
-
-
   Widget getItemAddCard(T item) {
     return addCardBuilder(item);
   }
@@ -209,7 +208,6 @@ class ListSetting<T extends ListItem> extends Setting<List<T>> {
     return cardBuilder(item, onDelete, onDuplicate);
   }
 
-
   @override
   dynamic valueToJson() {
     return _value.map((e) => e.toJson()).toList();
@@ -222,7 +220,6 @@ class ListSetting<T extends ListItem> extends Setting<List<T>> {
   }
 }
 
-
 class CustomSetting<T extends JsonSerializable> extends Setting<T> {
   // The screen that will be navigated to when this setting is tapped.
   Widget Function(BuildContext, CustomSetting<T>) screenBuilder;
diff --git a/lib/settings/types/setting_group.dart b/lib/settings/types/setting_group.dart
index f72263f7..c2a7cc41 100644
--- a/lib/settings/types/setting_group.dart
+++ b/lib/settings/types/setting_group.dart
@@ -171,6 +171,10 @@ class SettingGroup extends SettingItem {
     }
   }
 
+  bool isEqualTo(SettingGroup other) {
+    return json.encode(valueToJson()) == json.encode(other.valueToJson());
+  }
+
   @override
   dynamic valueToJson() {
     Json json = {};
diff --git a/lib/settings/types/setting_item.dart b/lib/settings/types/setting_item.dart
index 49d162c3..606c8587 100644
--- a/lib/settings/types/setting_item.dart
+++ b/lib/settings/types/setting_item.dart
@@ -16,11 +16,9 @@ abstract class SettingItem {
   // Settings which influence whether this setting is enabled
   List<EnableConditionEvaluator> enableSettings;
 
-  String displayName(BuildContext context) =>
-      getLocalizedName(context);
+  String displayName(BuildContext context) => getLocalizedName(context);
 
-  String displayDescription(BuildContext context) =>
-      getDescription(context);
+  String displayDescription(BuildContext context) => getDescription(context);
 
   bool get isEnabled {
     for (var enableSetting in enableSettings) {
@@ -48,8 +46,8 @@ abstract class SettingItem {
     return path.reversed.toList();
   }
 
-  SettingItem(
-      this.name, this.getLocalizedName, this.getDescription, this.searchTags, this.enableConditions )
+  SettingItem(this.name, this.getLocalizedName, this.getDescription,
+      this.searchTags, this.enableConditions)
       : id = name,
         _settingListeners = [],
         enableSettings = [];
diff --git a/lib/theme/types/color_scheme.dart b/lib/theme/types/color_scheme.dart
index 24be3a5c..ece52d7e 100644
--- a/lib/theme/types/color_scheme.dart
+++ b/lib/theme/types/color_scheme.dart
@@ -97,6 +97,22 @@ class ColorSchemeData extends ThemeItem {
 
   ColorSchemeData.fromJson(Json json)
       : super.fromJson(json, colorSchemeSettingsSchema.copy());
+
+  bool isEqualTo(ColorSchemeData other) {
+    return background == other.background &&
+        error == other.error &&
+        accent == other.accent &&
+        onError == other.onError &&
+        card == other.card &&
+        onCard == other.onCard &&
+        onAccent == other.onAccent &&
+        onBackground == other.onBackground &&
+        shadow == other.shadow &&
+        outline == other.outline &&
+        useAccentAsShadow == other.useAccentAsShadow &&
+        useAccentAsOutline == other.useAccentAsOutline &&
+        name == other.name;
+  }
 }
 
 ColorScheme getColorScheme(ColorSchemeData colorSchemeData) {
diff --git a/lib/theme/types/style_theme.dart b/lib/theme/types/style_theme.dart
index c4775334..f0be1244 100644
--- a/lib/theme/types/style_theme.dart
+++ b/lib/theme/types/style_theme.dart
@@ -40,7 +40,7 @@ class StyleTheme extends ThemeItem {
         .setValueWithoutNotify(borderWidth);
   }
 
-  StyleTheme.from(StyleTheme colorSchemeData) : super.from(colorSchemeData);
+  StyleTheme.from(StyleTheme super.colorSchemeData) : super.from();
 
   @override
   String get name => settings.getSetting("Name").value;
@@ -65,4 +65,14 @@ class StyleTheme extends ThemeItem {
 
   StyleTheme.fromJson(Json json)
       : super.fromJson(json, styleThemeSettingsSchema.copy());
+
+  bool isEqualTo(StyleTheme other) {
+    return name == other.name &&
+        shadowElevation == other.shadowElevation &&
+        shadowOpacity == other.shadowOpacity &&
+        shadowBlurRadius == other.shadowBlurRadius &&
+        shadowSpreadRadius == other.shadowSpreadRadius &&
+        borderRadius == other.borderRadius &&
+        borderWidth == other.borderWidth;
+  }
 }
diff --git a/lib/timer/types/time_duration.dart b/lib/timer/types/time_duration.dart
index fd7bc61f..7deeecf1 100644
--- a/lib/timer/types/time_duration.dart
+++ b/lib/timer/types/time_duration.dart
@@ -112,4 +112,18 @@ class TimeDuration extends JsonSerializable {
         minutes = json != null ? json['minutes'] ?? 0 : 0,
         seconds = json != null ? json['seconds'] ?? 0 : 0,
         milliseconds = json != null ? json['milliseconds'] ?? 0 : 0;
+
+  @override
+  bool operator ==(Object other) {
+    if (other is TimeDuration) {
+      return hours == other.hours &&
+          minutes == other.minutes &&
+          seconds == other.seconds &&
+          milliseconds == other.milliseconds;
+    }
+    return false;
+  }
+
+  @override
+  int get hashCode => Object.hash(hours, minutes, seconds, milliseconds);
 }
diff --git a/lib/timer/types/timer.dart b/lib/timer/types/timer.dart
index 87f8ca2f..6cd2b9e7 100644
--- a/lib/timer/types/timer.dart
+++ b/lib/timer/types/timer.dart
@@ -153,7 +153,7 @@ class ClockTimer extends CustomizableListItem {
   }
 
   Future<void> snooze() async {
-     TimeDuration addedDuration = TimeDuration(minutes: addLength.floor());
+    TimeDuration addedDuration = TimeDuration(minutes: addLength.floor());
     _currentDuration = addedDuration;
     _milliSecondsRemainingOnPause = addedDuration.inSeconds * 1000;
     await start();
@@ -262,4 +262,8 @@ class ClockTimer extends CustomizableListItem {
   copy() {
     return ClockTimer.from(this);
   }
+
+  bool isEqualTo(ClockTimer other) {
+    return _duration == other._duration && _settings.isEqualTo(other._settings);
+  }
 }
diff --git a/lib/timer/types/timer_preset.dart b/lib/timer/types/timer_preset.dart
index 4a15b3a6..aef325c5 100644
--- a/lib/timer/types/timer_preset.dart
+++ b/lib/timer/types/timer_preset.dart
@@ -1,6 +1,7 @@
 import 'package:clock_app/common/types/json.dart';
 import 'package:clock_app/common/types/list_item.dart';
 import 'package:clock_app/common/utils/id.dart';
+import 'package:clock_app/developer/logic/logger.dart';
 import 'package:clock_app/timer/types/time_duration.dart';
 
 class TimerPreset extends ListItem {
@@ -45,6 +46,10 @@ class TimerPreset extends ListItem {
     }
   }
 
+  bool isEqualTo(TimerPreset other) {
+    return name == other.name && duration == other.duration;
+  }
+
   @override
   copy() {
     return TimerPreset(name, duration);