Source: Roblox Creator Hub · CC BY 4.0 · View source · Code samples: MIT Imported 2026-10-03. Formatting adapted for this site.
ScriptProfilerService
Inherits from: Instance → Object
ScriptProfilerService provides a scripting interface to Roblox's Luau script profiler, which periodically samples running Luau threads to attribute CPU time to the functions that consume it.
Profiling is controlled independently for the server and for individual clients: ServerStart() and ServerStop() govern server-side scripts, while ClientStart() and ClientStop() govern a given player's client. Calling ServerRequestData() or ClientRequestData() collects a snapshot of the profiling results, which is delivered asynchronously through the OnNewData event as a JSON string. That string can be turned into a structured Luau table with DeserializeJSON().
This service powers the Script Profiler in the in-experience Developer Console.
Inherits from: Instance
Memory category: Instances
Tags: NotCreatable, Service
Methods
| Name | Type / Returns | Description |
|---|---|---|
| ScriptProfilerService:ClientRequestData | () | Requests the current script profiling data from the specified player's client. |
| ScriptProfilerService:ClientStart | () | Begins Luau script profiling for the specified player's client. |
| ScriptProfilerService:ClientStop | () | Stops Luau script profiling for the specified player's client. |
| ScriptProfilerService:DeserializeJSON | Dictionary | Parses a script-profiling JSON string into a structured Luau table. |
| ScriptProfilerService:ServerRequestData | () | Requests the current script profiling data from the server. |
| ScriptProfilerService:ServerStart | () | Begins Luau script profiling on the server. |
| ScriptProfilerService:ServerStop | () | Stops Luau script profiling on the server. |
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 |
ScriptProfilerService:ClientRequestData
Requests a snapshot of the profiling data collected for the given player's client. The data is not returned directly; instead it is delivered asynchronously through the OnNewData event as a JSON string.
When called on the server this replicates a data request to the target client, and when called on the client it gathers the local player's profiling data directly. On a client the player argument must be the local player.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
| player | Player | The Player whose client should report its profiling data. When called on a client, this must be the local player. |
Returns
| Type | Description |
|---|---|
| () |
| Field | Value |
|---|---|
| security | PluginSecurity |
| thread safety | Unsafe |
ScriptProfilerService:ClientStart
Begins profiling the Luau scripts running on the given player's client. The profiler periodically samples running Luau threads at frequency samples per second; if frequency is omitted it defaults to 1000, and a value outside the range [1, 10000] raises an error.
When called on the server this replicates a request to the target client to start profiling, and when called on the client it starts sampling the local player's scripts directly. On a client the player argument must be the local player.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
| player | Player | The Player whose client should start profiling. When called on a client, this must be the local player. | |
| frequency | int? | Optional sampling frequency in samples per second. Defaults to 1000 and must be within the range [1, 10000]. |
Returns
| Type | Description |
|---|---|
| () |
| Field | Value |
|---|---|
| security | PluginSecurity |
| thread safety | Unsafe |
ScriptProfilerService:ClientStop
Stops profiling the Luau scripts running on the given player's client.
When called on the server this replicates a request to the target client to stop profiling, and when called on the client it stops sampling the local player's scripts directly. On a client the player argument must be the local player.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
| player | Player | The Player whose client should stop profiling. When called on a client, this must be the local player. |
Returns
| Type | Description |
|---|---|
| () |
| Field | Value |
|---|---|
| security | PluginSecurity |
| thread safety | Unsafe |
ScriptProfilerService:DeserializeJSON
Converts the raw JSON produced by the profiler into a Luau table so the results can be inspected programmatically rather than parsed by hand. The returned table mirrors the profiling session, exposing entries such as its version, session start and end times, categories, call nodes, and function metadata.
An empty or non-object input yields no data.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
| jsonString | string? | The profiling data encoded as a JSON string, such as the value delivered by OnNewData. |
Returns
| Type | Description |
|---|---|
| Dictionary | A dictionary representing the parsed profiling data, including the session's categories, call nodes, and function metadata. |
| Field | Value |
|---|---|
| tags | ["CustomLuaState"] |
| security | PluginSecurity |
| thread safety | Unsafe |
ScriptProfilerService:ServerRequestData
Requests a snapshot of the profiling data collected on the server. The data is not returned directly; instead it is delivered asynchronously through the OnNewData event as a JSON string, with no associated player.
Returns
| Type | Description |
|---|---|
| () |
| Field | Value |
|---|---|
| security | PluginSecurity |
| thread safety | Unsafe |
ScriptProfilerService:ServerStart
Begins profiling the Luau scripts running on the server. The profiler periodically samples running Luau threads at frequency samples per second; if frequency is omitted it defaults to 1000, and a value outside the range [1, 10000] raises an error.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
| frequency | int? | Optional sampling frequency in samples per second. Defaults to 1000 and must be within the range [1, 10000]. |
Returns
| Type | Description |
|---|---|
| () |
| Field | Value |
|---|---|
| security | PluginSecurity |
| thread safety | Unsafe |
ScriptProfilerService:ServerStop
Stops profiling the Luau scripts running on the server.
Returns
| Type | Description |
|---|---|
| () |
| Field | Value |
|---|---|
| security | PluginSecurity |
| thread safety | Unsafe |
Events
| Name | Type / Returns | Description |
|---|---|---|
| ScriptProfilerService.OnNewData | Fires when a new profiling data snapshot becomes available after a data request. |
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. |
ScriptProfilerService.OnNewData
Fires when a new profiling snapshot becomes available, in response to ClientRequestData() or ServerRequestData(). The data is delivered as a JSON string in jsonString; pass it to DeserializeJSON() to obtain a structured table. player identifies the client the data came from, or is nil when the data was collected on the server.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
| player | Player | The Player whose client produced the data, or nil for data collected on the server. | |
| jsonString | string | The profiling data encoded as a JSON string. |
| Field | Value |
|---|---|
| security | PluginSecurity |
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 |