Source: Roblox Creator Hub · CC BY 4.0 · View source · Code samples: MIT Imported 2026-10-03. Formatting adapted for this site.
UnreliableRemoteEvent
Inherits from: BaseRemoteEvent → Instance → Object
The UnreliableRemoteEvent object is a variant of the RemoteEvent object. It facilitates asynchronous, unordered and unreliable, one-way communication across the client-server boundary without yielding for a response. This communication can be directed from one client to the server, from the server to a specific client, or from the server to all clients.
In order for both the server and clients to access a UnreliableRemoteEvent instance, it must be in a place where both sides can see it, such as ReplicatedStorage, although in some cases it's appropriate to store it in Workspace or inside a Tool.
UnreliableRemoteEvent is best used for ephemeral events, including effects that are only relevant for a short time, or for replicating continuously changing data. These events are not resent if they are lost and they do not wait for previously fired events to arrive before being processed, potentially resulting in reduced latency and network traffic. When you need ordering and reliability, use a RemoteEvent instead.
If no connected listener exists to handle an event, you might see a Remote event invocation discarded error in the log to indicate that the event was discarded and that you need to implement either OnClientEvent or OnServerEvent.
Throttling
Remote events are subject to rate limits when sent from the client to the server with the FireServer() method. RemoteEvents and UnreliableRemoteEvents both have a limit of approximately 500 requests per second, per client. This limit is shared among all remote events of the same type. To avoid throttling and latency issues, limit recurring remote events whenever possible.
Parameter limitations
Any type of Roblox object (Enum, Instance, etc.) can be passed as a parameter when an UnreliableRemoteEvent is fired, as well as Luau types such as numbers, strings, and booleans, although you should carefully explore the limitations.
Events with payloads larger than 1000 bytes are dropped. When this happens in Studio, a log message in the Output window indicates the number of bytes the event went over.
Like all events, the UnreliableRemoteEvent methods encode and compress certain object types, such as buffers, which shrinks the payload size and can make it difficult to verify whether you are under the limit prior to firing the event. If you frequently reach this limit, consider whether a standard RemoteEvent is the better fit for your use case.
Inherits from: BaseRemoteEvent
Memory category: Instances
Methods
| Name | Type / Returns | Description |
|---|---|---|
| UnreliableRemoteEvent:FireAllClients | () | Fires the OnClientEvent event for all connected clients. Has a 1000 byte limit to the payload of the event. Events with larger payloads are dropped. |
| UnreliableRemoteEvent:FireClient | () | Fires the OnClientEvent event for a specific client. Has a 1000 byte limit to the payload of the event. Events with larger payloads are dropped. |
| UnreliableRemoteEvent:FireServer | () | Fires the OnServerEvent event on the server from one connected client. Has a 1000 byte limit to the payload of the event. Events with larger payloads are dropped. |
Inherited from Instance
| Name | Type / Returns | Description |
|---|---|---|
| Instance:AddTag | () | Applies a tag to the instance. |
| Instance:children | Instances | Returns an array of the object's children. |
| Instance:ClearAllChildren | () | This method destroys all of an instance's children. |
| Instance:Clone | Instance | Create a copy of an instance and all its descendants, ignoring instances that are not Archivable. |
| Instance:clone | Instance | |
| Instance:Destroy | () | Sets the Instance.Parent property to nil, locks the Instance.Parent property, disconnects all connections, and calls Destroy() on all children. |
| Instance:destroy | () | |
| Instance:FindFirstAncestor | Instance? | Returns the first ancestor of the Instance whose Instance.Name is equal to the given name. |
| Instance:FindFirstAncestorOfClass | Instance? | Returns the first ancestor of the Instance whose Object.ClassName is equal to the given className. |
| Instance:FindFirstAncestorWhichIsA | Instance? | Returns the first ancestor of the Instance for whom Object:IsA() returns true for the given className. |
| Instance:FindFirstChild | Instance? | Returns the first child of the Instance found with the given name. |
| Instance:findFirstChild | Instance | |
| Instance:FindFirstChildOfClass | Instance? | Returns the first child of the Instance whose ClassName is equal to the given class name. |
| Instance:FindFirstChildWhichIsA | Instance? | Returns the first child of the Instance for whom Object:IsA() returns true for the given className. |
| Instance:FindFirstDescendant | Instance? | Returns the first descendant found with the given Instance.Name. |
| Instance:GetActor | Actor? | Returns the Actor associated with the Instance, if any. |
| Instance:GetAttribute | Variant | Returns the value which has been assigned to the given attribute name. |
| Instance:GetAttributeChangedSignal | RBXScriptSignal | Returns an event that fires when the given attribute changes. |
| Instance:GetAttributes | Dictionary | Returns a dictionary of the instance's attributes. |
| Instance:GetChildren | Instances | Returns an array containing all of the instance's children. |
| Instance:getChildren | Instances | |
| Instance:GetDebugId | string | Returns a coded string of the debug ID used internally by Roblox. |
| Instance:GetDescendants | Instances | Returns an array containing all of the descendants of the instance. |
| Instance:GetFullName | string | Returns a string describing the instance's ancestry. |
| Instance:GetStyled | Variant | Returns the styled or explicitly modified value of the specified property, or else the default property value if it hasn't been styled/modified. |
| Instance:GetStyledPropertyChangedSignal | RBXScriptSignal | Returns an event that fires when the given style property changes on the instance. |
| Instance:GetTags | Array | Gets an array of all tags applied to the instance. |
| Instance:HasTag | boolean | Check whether the instance has a given tag. |
| Instance:IsAncestorOf | boolean | Returns true if an Instance is an ancestor of the given descendant. |
| Instance:IsDescendantOf | boolean | Returns true if an Instance is a descendant of the given ancestor. |
| Instance:isDescendantOf | boolean | |
| Instance:IsPropertyModified | boolean | Returns true if the value stored in the specified property is not equal to the code-instantiated default. |
| Instance:QueryDescendants | Instances | Returns an array containing all descendants of the instance that match the selector string. |
| Instance:Remove | () | Sets the object's Parent to nil, and does the same for all its descendants. |
| Instance:remove | () | |
| Instance:RemoveTag | () | Removes a tag from the instance. |
| Instance:ResetPropertyToDefault | () | Resets a property to its default value. |
| Instance:SetAttribute | () | Sets the attribute with the given name to the given value. |
| Instance:WaitForChild | Instance | Returns the child of the Instance with the given name. If the child does not exist, it will yield the current thread until it does. |
Inherited from Object
| Name | Type / Returns | Description |
|---|---|---|
| Object:GetPropertyChangedSignal | RBXScriptSignal | Get an event that fires when a given property of the object changes. |
| Object:IsA | boolean | Returns true if an object's class matches or inherits from a given class. |
| Object:isA | boolean |
UnreliableRemoteEvent:FireAllClients
Fires the OnClientEvent event for all connected clients. Unlike FireClient(), this event does not take a target Player as the first argument, since it fires to multiple clients. Since this method is used to communicate from the server to clients, it only works when used in a Script.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
| arguments | Tuple | Values to pass to all OnClientEvent events connected to the same UnreliableRemoteEvent. |
Returns
| Type | Description |
|---|---|
| () |
| Field | Value |
|---|---|
| security | None |
| thread safety | Unsafe |
| capabilities | ["RemoteEvent"] |
UnreliableRemoteEvent:FireClient
Fires the OnClientEvent event for the specific client in the required Player argument. Since this method is used to communicate from the server to a client, it only works when used in a Script.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
| player | Player | The client of the Player to fire the event to. | |
| arguments | Tuple | Values to pass to OnClientEvent events connected to the same UnreliableRemoteEvent. |
Returns
| Type | Description |
|---|---|
| () |
| Field | Value |
|---|---|
| security | None |
| thread safety | Unsafe |
| capabilities | ["RemoteEvent"] |
UnreliableRemoteEvent:FireServer
Fires the OnServerEvent event on the server from one connected client. Connected events receive the Player argument of the firing client. Since this method is used to communicate from a client to the server, it only works when used in a client script.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
| arguments | Tuple | Values to pass to OnServerEvent events connected to the same UnreliableRemoteEvent. |
Returns
| Type | Description |
|---|---|
| () |
| Field | Value |
|---|---|
| security | None |
| thread safety | Unsafe |
| capabilities | ["RemoteEvent"] |
Events
| Name | Type / Returns | Description |
|---|---|---|
| UnreliableRemoteEvent.OnClientEvent | Fires from a LocalScript when either FireClient() or FireAllClients() is called on the same UnreliableRemoteEvent instance from a Script, although this firing is not guaranteed even if one of the above methods are called. This can occur due to packet loss or to maintain optimal engine performance. | |
| UnreliableRemoteEvent.OnServerEvent | Fires from a Script when FireServer() is called on the same UnreliableRemoteEvent instance from a LocalScript, although this firing is not guaranteed even if the above methods is called. This can occur due to packet loss or to maintain optimal engine performance. |
Inherited from Instance
| Name | Type / Returns | Description |
|---|---|---|
| Instance.AncestryChanged | Fires when the Instance.Parent property of this object or one of its ancestors is changed. | |
| Instance.AttributeChanged | Fires whenever an attribute is changed on the Instance. | |
| Instance.ChildAdded | Fires after an object is parented to this Instance. | |
| Instance.childAdded | ||
| Instance.ChildRemoved | Fires after a child is removed from this Instance. | |
| Instance.DescendantAdded | Fires after a descendant is added to the Instance. | |
| Instance.DescendantRemoving | Fires immediately before a descendant of the Instance is removed. | |
| Instance.Destroying | Fires immediately before (or is deferred until after) the instance is destroyed via Instance:Destroy(). | |
| Instance.StyledPropertiesChanged | Fires whenever any style property is changed on the instance, including when a property is set to nil. |
Inherited from Object
| Name | Type / Returns | Description |
|---|---|---|
| Object.Changed | Fires immediately after a property of the object changes, with some limitations. |
UnreliableRemoteEvent.OnClientEvent
Fires from a LocalScript when either FireClient() or FireAllClients() is called on the same UnreliableRemoteEvent instance from a Script, although this firing is not guaranteed even if one of the above methods are called. This can occur due to packet loss or to maintain optimal engine performance.
Also note that it is not guaranteed that the order of events will match the order of FireClient() or FireAllClients() calls.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
| arguments | Tuple | The parameters sent through FireClient() or FireAllClients(). |
| Field | Value |
|---|---|
| security | None |
| capabilities | ["RemoteEvent"] |
UnreliableRemoteEvent.OnServerEvent
Fires from a Script when FireServer() is called on the same UnreliableRemoteEvent instance from a LocalScript, although this firing is not guaranteed even if the above methods is called. This can occur due to packet loss or to maintain optimal engine performance.
Also note that it is not guaranteed that the order of events will match the order of FireServer() calls.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
| player | Player | The Player associated with the client that the FireServer() call originates from. | |
| arguments | Tuple | The parameters sent through FireServer(). |
| Field | Value |
|---|---|
| security | None |
| capabilities | ["RemoteEvent"] |
Properties
Inherited from Instance
| Name | Type / Returns | Description |
|---|---|---|
| Instance.Archivable | boolean | Determines if an Instance and its descendants can be cloned using Instance:Clone(), and can be saved/published. |
| Instance.archivable | boolean | |
| Instance.Capabilities | SecurityCapabilities | The set of capabilities allowed to be used for scripts inside this container. |
| Instance.IsInSandbox | boolean | Indicates whether the instance is inside a sandboxed container. |
| Instance.Name | string | A non-unique identifier of the Instance. |
| Instance.Parent | Instance | Determines the hierarchical parent of the Instance. |
| Instance.PredictionMode | PredictionMode | Reflects the client-side prediction mode applied to the instance under server-authoritative physics. |
| Instance.RobloxLocked | boolean | A deprecated property that used to protect CoreGui objects. |
| Instance.Sandboxed | boolean | When enabled, the instance can only access abilities in its Capabilities list. |
| Instance.UniqueId | UniqueId | A unique identifier for the instance. |
Inherited from Object
| Name | Type / Returns | Description |
|---|---|---|
| Object.ClassName | string | A read-only string representing the class this Object belongs to. |
| Object.className | string |