Source: Roblox Creator Hub · CC BY 4.0 · View source · Code samples: MIT Imported 2026-10-03. Formatting adapted for this site.
UICorner
Inherits from: UIComponent → UIBase → Instance → Object
UICorner is a modifier which applies deformation to corners of its parent GuiObject. Input, but not descendants, will be clipped to the round corner area. See UI appearance modifiers for examples.
In order to keep the circular shape of round corners, each corner radius (UDim) is internally calculated as follows:
- The radius of the X axis is always the same as the radius of Y axis.
Scalerounding will always apply to the minimum width or height.- Rounded rectangles will always be in a "pill" shape if
CornerRadiusis set to a value that leads to a calculated result greater than half of the rectangle's minimum width or height.
Alternatively to UICorner, rounded corners can be accomplished using slices which are suitable for decorative borders that are not simply rounded. See 9‑Slice Design for details.
Note that UICorner can not be applied to a ScrollingFrame.
Individual Corners
Each corner has its own radius property (TopLeftRadius, TopRightRadius, BottomRightRadius, BottomLeftRadius). The CornerRadius property is a convenience shorthand that sets all four corners at once and reads from TopLeftRadius.
When using styling with UICorner, avoid configuring both CornerRadius and the individual corner radii in style rules at the same time, as this may produce unexpected results.
Inherits from: UIComponent
Memory category: Instances
Properties
| Name | Type / Returns | Description |
|---|---|---|
| UICorner.BottomLeftRadius | UDim | Determines the radius of the bottom-left corner. |
| UICorner.BottomRightRadius | UDim | Determines the radius of the bottom-right corner. |
| UICorner.CornerRadius | UDim | Sets all four corner radii at once and reads from TopLeftRadius. |
| UICorner.TopLeftRadius | UDim | Determines the radius of the top-left corner. |
| UICorner.TopRightRadius | UDim | Determines the radius of the top-right corner. |
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 |
UICorner.BottomLeftRadius
This property is currently in beta. To use it, enable New UI Capabilities in Studio's beta features window.
A UDim property that determines the radius of the bottom-left corner independently. Setting CornerRadius overwrites all four individual corner radii to the same value.
| Field | Value |
|---|---|
| type | UDim |
| security | {"read":"None","write":"None"} |
| thread safety | ReadSafe |
| category | Individual Corners |
| serialization | {"can_load":true,"can_save":true} |
| capabilities | ["UI"] |
UICorner.BottomRightRadius
This property is currently in beta. To use it, enable New UI Capabilities in Studio's beta features window.
A UDim property that determines the radius of the bottom-right corner independently. Setting CornerRadius overwrites all four individual corner radii to the same value.
| Field | Value |
|---|---|
| type | UDim |
| security | {"read":"None","write":"None"} |
| thread safety | ReadSafe |
| category | Individual Corners |
| serialization | {"can_load":true,"can_save":true} |
| capabilities | ["UI"] |
UICorner.CornerRadius
A convenience UDim property that acts as a shorthand for the four individual corner radius properties. Writing to this property sets TopLeftRadius, TopRightRadius, BottomRightRadius, and BottomLeftRadius to the same value. Reading this property returns the value of TopLeftRadius.
| Field | Value |
|---|---|
| type | UDim |
| tags | ["NotReplicated"] |
| security | {"read":"None","write":"None"} |
| thread safety | ReadSafe |
| category | Appearance |
| serialization | {"can_load":true,"can_save":false} |
| capabilities | ["UI"] |
UICorner.TopLeftRadius
This property is currently in beta. To use it, enable New UI Capabilities in Studio's beta features window.
A UDim property that determines the radius of the top-left corner independently. Setting CornerRadius overwrites all four individual corner radii to the same value.
| Field | Value |
|---|---|
| type | UDim |
| security | {"read":"None","write":"None"} |
| thread safety | ReadSafe |
| category | Individual Corners |
| serialization | {"can_load":true,"can_save":true} |
| capabilities | ["UI"] |
UICorner.TopRightRadius
This property is currently in beta. To use it, enable New UI Capabilities in Studio's beta features window.
A UDim property that determines the radius of the top-right corner independently. Setting CornerRadius overwrites all four individual corner radii to the same value.
| Field | Value |
|---|---|
| type | UDim |
| security | {"read":"None","write":"None"} |
| thread safety | ReadSafe |
| category | Individual Corners |
| serialization | {"can_load":true,"can_save":true} |
| capabilities | ["UI"] |
Methods
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 |
Events
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. |