diff --git a/SabreTools.Serialization/Internal.OfflineList.cs b/SabreTools.Serialization/Internal.OfflineList.cs
index e0a81f46..45880d02 100644
--- a/SabreTools.Serialization/Internal.OfflineList.cs
+++ b/SabreTools.Serialization/Internal.OfflineList.cs
@@ -1,3 +1,6 @@
+using System.Collections.Generic;
+using System.Linq;
+
 namespace SabreTools.Serialization
 {
     /// <summary>
@@ -7,6 +10,55 @@ namespace SabreTools.Serialization
     {
         #region Serialize
 
+        /// <summary>
+        /// Convert from <cref="Models.OfflineList.Game"/> to <cref="Models.Internal.Machine"/>
+        /// </summary>
+        public static Models.Internal.Machine ConvertMachineFromOfflineList(Models.OfflineList.Game item)
+        {
+            var machine = new Models.Internal.Machine
+            {
+                [Models.Internal.Machine.ImageNumberKey] = item.ImageNumber,
+                [Models.Internal.Machine.ReleaseNumberKey] = item.ReleaseNumber,
+                [Models.Internal.Machine.NameKey] = item.Title,
+                [Models.Internal.Machine.SaveTypeKey] = item.SaveType,
+                [Models.Internal.Machine.PublisherKey] = item.Publisher,
+                [Models.Internal.Machine.LocationKey] = item.Location,
+                [Models.Internal.Machine.SourceRomKey] = item.SourceRom,
+                [Models.Internal.Machine.LanguageKey] = item.Language,
+                [Models.Internal.Machine.Im1CRCKey] = item.Im1CRC,
+                [Models.Internal.Machine.Im2CRCKey] = item.Im2CRC,
+                [Models.Internal.Machine.CommentKey] = item.Comment,
+                [Models.Internal.Machine.DuplicateIDKey] = item.DuplicateID,
+            };
+
+            if (item.Files?.RomCRC != null && item.Files.RomCRC.Any())
+            {
+                var roms = new List<Models.Internal.Rom>();
+                foreach (var file in item.Files.RomCRC)
+                {
+                    var rom = ConvertFromOfflineList(file);
+                    rom[Models.Internal.Rom.SizeKey] = item.RomSize;
+                    roms.Add(rom);
+                }
+                machine[Models.Internal.Machine.RomKey] = roms.ToArray();
+            }
+
+            return machine;
+        }
+
+        /// <summary>
+        /// Convert from <cref="Models.OfflineList.Files"/> to an array of <cref="Models.Internal.Rom"/>
+        /// </summary>
+        public static Models.Internal.Rom[] ConvertFromOfflineList(Models.OfflineList.Files item)
+        {
+            var roms = new List<Models.Internal.Rom>();
+            foreach (var romCRC in item.RomCRC)
+            {
+                roms.Add(ConvertFromOfflineList(romCRC));
+            }
+            return roms.ToArray();
+        }
+
         /// <summary>
         /// Convert from <cref="Models.OfflineList.FileRomCRC"/> to <cref="Models.Internal.Rom"/>
         /// </summary>
@@ -24,6 +76,54 @@ namespace SabreTools.Serialization
 
         #region Deserialize
 
+        /// <summary>
+        /// Convert from <cref="Models.Internal.Machine"/> to <cref="Models.OfflineList.Game"/>
+        /// </summary>
+        public static Models.OfflineList.Game ConvertMachineToOfflineList(Models.Internal.Machine item)
+        {
+            var game = new Models.OfflineList.Game
+            {
+                ImageNumber = item.ReadString(Models.Internal.Machine.ImageNumberKey),
+                ReleaseNumber = item.ReadString(Models.Internal.Machine.ReleaseNumberKey),
+                Title = item.ReadString(Models.Internal.Machine.NameKey),
+                SaveType = item.ReadString(Models.Internal.Machine.SaveTypeKey),
+                Publisher = item.ReadString(Models.Internal.Machine.PublisherKey),
+                Location = item.ReadString(Models.Internal.Machine.LocationKey),
+                SourceRom = item.ReadString(Models.Internal.Machine.SourceRomKey),
+                Language = item.ReadString(Models.Internal.Machine.LanguageKey),
+                Im1CRC = item.ReadString(Models.Internal.Machine.Im1CRCKey),
+                Im2CRC = item.ReadString(Models.Internal.Machine.Im2CRCKey),
+                Comment = item.ReadString(Models.Internal.Machine.CommentKey),
+                DuplicateID = item.ReadString(Models.Internal.Machine.DuplicateIDKey),
+            };
+
+            if (item.ContainsKey(Models.Internal.Machine.RomKey) && item[Models.Internal.Machine.RomKey] is Models.Internal.Rom[] roms)
+            {
+                var romCRCItems = new List<Models.OfflineList.FileRomCRC>();
+                foreach (var rom in roms)
+                {
+                    game.RomSize ??= rom.ReadString(Models.Internal.Rom.SizeKey);
+                    romCRCItems.Add(ConvertToOfflineList(rom));
+                }
+                game.Files = new Models.OfflineList.Files { RomCRC = romCRCItems.ToArray() };
+            }
+
+            return game;
+        }
+
+        /// <summary>
+        /// Convert from an array of <cref="Models.Internal.Rom"/> to <cref="Models.OfflineList.FileRomCRC"/>
+        /// </summary>
+        public static Models.OfflineList.Files ConvertToOfflineList(Models.Internal.Rom[] items)
+        {
+            var romCRCs = new List<Models.OfflineList.FileRomCRC>();
+            foreach (var item in items)
+            {
+                romCRCs.Add(ConvertToOfflineList(item));
+            }
+            return new Models.OfflineList.Files() { RomCRC = romCRCs.ToArray() };
+        }
+
         /// <summary>
         /// Convert from <cref="Models.Internal.Rom"/> to <cref="Models.OfflineList.FileRomCRC"/>
         /// </summary>