diff --git a/OpenDreamClient/Interface/Controls/ControlBrowser.cs b/OpenDreamClient/Interface/Controls/ControlBrowser.cs
index fb5f58fdb8..98c98e1800 100644
--- a/OpenDreamClient/Interface/Controls/ControlBrowser.cs
+++ b/OpenDreamClient/Interface/Controls/ControlBrowser.cs
@@ -113,16 +113,21 @@ private void RequestHandler(IRequestHandlerContext context) {
             Stream stream;
             HttpStatusCode status;
             var path = new ResPath(newUri.AbsolutePath);
-            try {
-                stream = _resourceManager.UserData.OpenRead(_dreamResource.GetCacheFilePath(newUri.AbsolutePath));
-                status = HttpStatusCode.OK;
-            } catch (FileNotFoundException) {
+            if(!_dreamResource.EnsureCacheFile(newUri.AbsolutePath)) {
                 stream = Stream.Null;
                 status = HttpStatusCode.NotFound;
-            } catch (Exception e) {
-                _sawmill.Error($"Exception while loading file from {newUri}:\n{e}");
-                stream = Stream.Null;
-                status = HttpStatusCode.InternalServerError;
+            } else {
+                try {
+                    stream = _resourceManager.UserData.OpenRead(_dreamResource.GetCacheFilePath(newUri.AbsolutePath));
+                    status = HttpStatusCode.OK;
+                } catch (FileNotFoundException) {
+                    stream = Stream.Null;
+                    status = HttpStatusCode.NotFound;
+                } catch (Exception e) {
+                    _sawmill.Error($"Exception while loading file from {newUri}:\n{e}");
+                    stream = Stream.Null;
+                    status = HttpStatusCode.InternalServerError;
+                }
             }
 
             if (!FileExtensionMimeTypes.TryGetValue(path.Extension, out var mimeType))
diff --git a/OpenDreamClient/Resources/DreamResourceManager.cs b/OpenDreamClient/Resources/DreamResourceManager.cs
index ef4eb7c7eb..0d71813f9c 100644
--- a/OpenDreamClient/Resources/DreamResourceManager.cs
+++ b/OpenDreamClient/Resources/DreamResourceManager.cs
@@ -4,7 +4,6 @@
 using Robust.Shared.Configuration;
 using Robust.Shared.ContentPack;
 using Robust.Shared.Network;
-using Robust.Shared.Timing;
 using Robust.Shared.Utility;
 
 namespace OpenDreamClient.Resources {
@@ -23,6 +22,7 @@ public interface IDreamResourceManager {
         /// <typeparam name="T">The type of resource to load as.</typeparam>
         void LoadResourceAsync<T>(int resourceId, Action<T> onLoadCallback) where T : DreamResource;
         ResPath GetCacheFilePath(string filename);
+        public bool EnsureCacheFile(string filename, int timeoutSeconds = 5);
     }
 
     internal sealed class DreamResourceManager : IDreamResourceManager {
@@ -38,11 +38,14 @@ internal sealed class DreamResourceManager : IDreamResourceManager {
 
         private ISawmill _sawmill = default!;
 
+        private readonly HashSet<string> _activeBrowseRscRequests = new();
+
         public void Initialize() {
             _sawmill = Logger.GetSawmill("opendream.res");
             InitCacheDirectory();
 
             _netManager.RegisterNetMessage<MsgBrowseResource>(RxBrowseResource);
+            _netManager.RegisterNetMessage<MsgBrowseResourceResponse>(RxBrowseResourceResponse);
             _netManager.RegisterNetMessage<MsgRequestResource>();
             _netManager.RegisterNetMessage<MsgResource>(RxResource);
         }
@@ -64,7 +67,23 @@ private void InitCacheDirectory() {
         }
 
         private void RxBrowseResource(MsgBrowseResource message) {
-            CreateCacheFile(message.Filename, message.Data);
+            _sawmill.Debug($"Received cache check for {message.Filename}");
+            if(_resourceManager.UserData.Exists(GetCacheFilePath(message.Filename))){ //TODO CHECK HASH
+                _sawmill.Debug($"Cache hit for {message.Filename}");
+            } else {
+                _sawmill.Debug($"Cache miss for {message.Filename}, requesting from server.");
+                _activeBrowseRscRequests.Add(message.Filename);
+                _netManager.ServerChannel?.SendMessage(new MsgBrowseResourceRequest(){ Filename = message.Filename});
+            }
+        }
+
+        private void RxBrowseResourceResponse(MsgBrowseResourceResponse message) {
+            if(_activeBrowseRscRequests.Contains(message.Filename)) {
+                _activeBrowseRscRequests.Remove(message.Filename);
+                CreateCacheFile(message.Filename, message.Data);
+            } else {
+                _sawmill.Error($"Recieved a browse_rsc response for a file we didn't ask for: {message.Filename}");
+            }
         }
 
         private void RxResource(MsgResource message) {
@@ -121,7 +140,7 @@ public void LoadResourceAsync<T>(int resourceId, Action<T> onLoadCallback) where
                 _netManager.ClientSendMessage(msg);
 
                 var timeout = _cfg.GetCVar(OpenDreamCVars.DownloadTimeout);
-                Timer.Spawn(TimeSpan.FromSeconds(timeout), () => {
+                Robust.Shared.Timing.Timer.Spawn(TimeSpan.FromSeconds(timeout), () => {
                     if (_loadingResources.ContainsKey(resourceId)) {
                         _sawmill.Warning(
                             $"Resource id {resourceId} was requested, but is still not received {timeout} seconds later.");
@@ -163,6 +182,31 @@ public ResPath CreateCacheFile(string filename, byte[] data)
             return new ResPath(filename);
         }
 
+        /// <summary>
+        /// Blocking check for the existence of a cached file from `browse_rsc()`. Returns true when the file is ready, or returns false if the file is not ready within timeoutSeconds.
+        /// </summary>
+        /// <param name="filename">filepath of the cached resource (eg `./foo.png`)</param>
+        /// <param name="timeoutSeconds">how long to block for while waiting for the resource. Default 5 seconds.</param>
+        /// <returns></returns>
+        public bool EnsureCacheFile(string filename, int timeoutSeconds = 5) {
+            var actualPath = GetCacheFilePath(filename);
+            if(_resourceManager.UserData.Exists(actualPath)) {
+                return true;
+            } else {
+                if(_activeBrowseRscRequests.Contains(actualPath.Filename)) {
+                    //block until the file arrives for like 5 seconds, then give up
+                    DateTime thresholdTime = DateTime.Now.AddSeconds(timeoutSeconds);
+                    while(!_resourceManager.UserData.Exists(actualPath) && DateTime.Now < thresholdTime) {
+                        _netManager.ProcessPackets(); //todo this should be sleep
+                    }
+                    return _resourceManager.UserData.Exists(actualPath);
+                } else {
+                    _sawmill.Error("Cache was ensured for a file that does not exist in cache and is not requested. Probably someobody called browse() without browse_rsc() first.");
+                    return false;
+                }
+            }
+        }
+
         private DreamResource? GetCachedResource(int resourceId) {
             _resourceCache.TryGetValue(resourceId, out var cached);
 
diff --git a/OpenDreamRuntime/DreamConnection.cs b/OpenDreamRuntime/DreamConnection.cs
index 071f3a91b9..cf4bc36376 100644
--- a/OpenDreamRuntime/DreamConnection.cs
+++ b/OpenDreamRuntime/DreamConnection.cs
@@ -77,7 +77,7 @@ public DreamObjectMovable? Eye {
     [ViewVariables] private string _selectedStatPanel;
     [ViewVariables] private readonly Dictionary<int, Action<DreamValue>> _promptEvents = new();
     [ViewVariables] private int _nextPromptEvent = 1;
-
+    private readonly Dictionary<string, DreamResource> _permittedBrowseRscFiles = new();
     private DreamObjectMob? _mob;
     private DreamObjectMovable? _eye;
 
@@ -399,10 +399,25 @@ public void BrowseResource(DreamResource resource, string filename) {
 
         var msg = new MsgBrowseResource() {
             Filename = filename,
-            Data = resource.ResourceData
+            DataHash = resource.ResourceData.Length //TODO: make a quick hash that can work clientside too
         };
+        _permittedBrowseRscFiles.Add(filename, resource);
+
+        Session?.Channel.SendMessage(msg);
+    }
+
+    public void HandleBrowseResourceRequest(string filename) {
+        if(_permittedBrowseRscFiles.TryGetValue(filename, out var dreamResource)) {
+            var msg = new MsgBrowseResourceResponse() {
+                Filename = filename,
+                Data = dreamResource.ResourceData! //honestly if this is null, something mega fucked up has happened and we should error hard
+            };
+            _permittedBrowseRscFiles.Remove(filename);
+            Session?.Channel.SendMessage(msg);
+        } else {
+            _sawmill.Error($"Client({Session}) requested a browse_rsc file they had not been permitted to request ({filename}).");
+        }
 
-        Session?.ConnectedClient.SendMessage(msg);
     }
 
     public void Browse(string? body, string? options) {
diff --git a/OpenDreamRuntime/DreamManager.Connections.cs b/OpenDreamRuntime/DreamManager.Connections.cs
index 7077a15e01..ceed48dbfa 100644
--- a/OpenDreamRuntime/DreamManager.Connections.cs
+++ b/OpenDreamRuntime/DreamManager.Connections.cs
@@ -54,6 +54,8 @@ private void InitializeConnectionManager() {
             _netManager.RegisterNetMessage<MsgPromptList>();
             _netManager.RegisterNetMessage<MsgPromptResponse>(RxPromptResponse);
             _netManager.RegisterNetMessage<MsgBrowseResource>();
+            _netManager.RegisterNetMessage<MsgBrowseResourceRequest>(RxBrowseResourceRequest);
+            _netManager.RegisterNetMessage<MsgBrowseResourceResponse>();
             _netManager.RegisterNetMessage<MsgBrowse>();
             _netManager.RegisterNetMessage<MsgTopic>(RxTopic);
             _netManager.RegisterNetMessage<MsgWinSet>();
@@ -224,6 +226,11 @@ private void RxAckLoadInterface(MsgAckLoadInterface message) {
             _playerManager.JoinGame(player);
         }
 
+        private void RxBrowseResourceRequest(MsgBrowseResourceRequest message) {
+            var connection = ConnectionForChannel(message.MsgChannel);
+            connection.HandleBrowseResourceRequest(message.Filename);
+        }
+
         private DreamConnection ConnectionForChannel(INetChannel channel) {
             return _connections[_playerManager.GetSessionByChannel(channel).UserId];
         }
diff --git a/OpenDreamShared/Network/Messages/MsgBrowseResource.cs b/OpenDreamShared/Network/Messages/MsgBrowseResource.cs
index d0c1983338..b2ca8e2870 100644
--- a/OpenDreamShared/Network/Messages/MsgBrowseResource.cs
+++ b/OpenDreamShared/Network/Messages/MsgBrowseResource.cs
@@ -1,26 +1,22 @@
-using System;
-using Lidgren.Network;
+using Lidgren.Network;
 using Robust.Shared.Network;
 using Robust.Shared.Serialization;
 
-namespace OpenDreamShared.Network.Messages {
-    public sealed class MsgBrowseResource : NetMessage {
-        // TODO: Browse should be on its own channel or something.
-        public override MsgGroups MsgGroup => MsgGroups.EntityEvent;
+namespace OpenDreamShared.Network.Messages;
+public sealed class MsgBrowseResource : NetMessage {
+    // TODO: Browse should be on its own channel or something.
+    public override MsgGroups MsgGroup => MsgGroups.EntityEvent;
 
-        public string Filename = String.Empty;
-        public byte[] Data = Array.Empty<byte>();
+    public string Filename = string.Empty;
+    public int DataHash;
 
-        public override void ReadFromBuffer(NetIncomingMessage buffer, IRobustSerializer serializer) {
-            Filename = buffer.ReadString();
-            var bytes = buffer.ReadVariableInt32();
-            Data = buffer.ReadBytes(bytes);
-        }
+    public override void ReadFromBuffer(NetIncomingMessage buffer, IRobustSerializer serializer) {
+        Filename = buffer.ReadString();
+        DataHash = buffer.ReadVariableInt32();
+    }
 
-        public override void WriteToBuffer(NetOutgoingMessage buffer, IRobustSerializer serializer) {
-            buffer.Write(Filename);
-            buffer.WriteVariableInt32(Data.Length);
-            buffer.Write(Data);
-        }
+    public override void WriteToBuffer(NetOutgoingMessage buffer, IRobustSerializer serializer) {
+        buffer.Write(Filename);
+        buffer.WriteVariableInt32(DataHash);
     }
 }
diff --git a/OpenDreamShared/Network/Messages/MsgBrowseResourceRequest.cs b/OpenDreamShared/Network/Messages/MsgBrowseResourceRequest.cs
new file mode 100644
index 0000000000..f860e5724e
--- /dev/null
+++ b/OpenDreamShared/Network/Messages/MsgBrowseResourceRequest.cs
@@ -0,0 +1,19 @@
+using Lidgren.Network;
+using Robust.Shared.Network;
+using Robust.Shared.Serialization;
+
+namespace OpenDreamShared.Network.Messages;
+public sealed class MsgBrowseResourceRequest : NetMessage {
+    // TODO: Browse should be on its own channel or something.
+    public override MsgGroups MsgGroup => MsgGroups.EntityEvent;
+
+    public string Filename = string.Empty;
+
+    public override void ReadFromBuffer(NetIncomingMessage buffer, IRobustSerializer serializer) {
+        Filename = buffer.ReadString();
+    }
+
+    public override void WriteToBuffer(NetOutgoingMessage buffer, IRobustSerializer serializer) {
+        buffer.Write(Filename);
+    }
+}
diff --git a/OpenDreamShared/Network/Messages/MsgBrowseResourceResponse.cs b/OpenDreamShared/Network/Messages/MsgBrowseResourceResponse.cs
new file mode 100644
index 0000000000..4f954737a0
--- /dev/null
+++ b/OpenDreamShared/Network/Messages/MsgBrowseResourceResponse.cs
@@ -0,0 +1,24 @@
+using Lidgren.Network;
+using Robust.Shared.Network;
+using Robust.Shared.Serialization;
+
+namespace OpenDreamShared.Network.Messages;
+public sealed class MsgBrowseResourceResponse : NetMessage {
+    // TODO: Browse should be on its own channel or something.
+    public override MsgGroups MsgGroup => MsgGroups.EntityEvent;
+
+    public string Filename = string.Empty;
+    public byte[] Data = [];
+
+    public override void ReadFromBuffer(NetIncomingMessage buffer, IRobustSerializer serializer) {
+        Filename = buffer.ReadString();
+        var bytes = buffer.ReadVariableInt32();
+        Data = buffer.ReadBytes(bytes);
+    }
+
+    public override void WriteToBuffer(NetOutgoingMessage buffer, IRobustSerializer serializer) {
+        buffer.Write(Filename);
+        buffer.WriteVariableInt32(Data.Length);
+        buffer.Write(Data);
+    }
+}
diff --git a/TestGame/code.dm b/TestGame/code.dm
index c6f0d1c214..550c04c673 100644
--- a/TestGame/code.dm
+++ b/TestGame/code.dm
@@ -48,6 +48,9 @@
 		usr << "menus: [json_encode(winget(usr, null, "menus"))]"
 		usr << "macros: [json_encode(winget(usr, null, "macros"))]"
 
+	verb/browse_rsc_test()
+		usr << browse_rsc('icons/mob.dmi', "mobicon.png")
+		usr << browse("<p><img src=mobicon.png></p>Oh look, it's you!","window=honk")
 
 	verb/rotate()
 		for(var/i in 1 to 8)