---
name: UITextSizeConstraint
last_updated: 2026-06-10T23:09:12Z
inherits:
  - UIConstraint
  - UIComponent
  - UIBase
  - Instance
  - Object
type: class
memory_category: Instances
summary: "Ensures that the size of text rendered by certain GuiObject classes lies within the range described by MaxTextSize and MinTextSize."
---

# Class: UITextSizeConstraint

> Ensures that the size of text rendered by certain [GuiObject](/docs/reference/engine/classes/GuiObject.md) classes
> lies within the range described by
> [MaxTextSize](/docs/reference/engine/classes/UITextSizeConstraint.md) and
> [MinTextSize](/docs/reference/engine/classes/UITextSizeConstraint.md).

## Description

A **UITextSizeConstraint** ensures that the size of text rendered by certain
[GuiObject](/docs/reference/engine/classes/GuiObject.md) classes ([TextLabel](/docs/reference/engine/classes/TextLabel.md), [TextButton](/docs/reference/engine/classes/TextButton.md), or
[TextBox](/docs/reference/engine/classes/TextBox.md)) lies within the range described by
[MaxTextSize](/docs/reference/engine/classes/UITextSizeConstraint.md) and
[MinTextSize](/docs/reference/engine/classes/UITextSizeConstraint.md). It is meant to be used
alongside [TextLabel.TextScaled](/docs/reference/engine/classes/TextLabel.md), which automatically scales text to
fill its containing object. Like other UI constraints, it is applied when
parented to the object to be constrained.

It's recommended that no values lower than 9 be used for
[MinTextSize](/docs/reference/engine/classes/UITextSizeConstraint.md) property, otherwise text
may not be readable to most users.

## Properties

### Property: UITextSizeConstraint.MaxTextSize

```json
{
  "type": "int",
  "access": "ReadWrite",
  "security": {
    "read": "None",
    "write": "None"
  },
  "serialization": {
    "can_load": true,
    "can_save": true
  },
  "thread_safety": "ReadSafe",
  "category": "Behavior",
  "capabilities": [
    "UI"
  ]
}
```

This property indicates the largest size in pixels the font is allowed to
be. It defaults to 1000 pixels and must be set larger than or equal to the
[MinTextSize](/docs/reference/engine/classes/UITextSizeConstraint.md) property.

If the affected [GuiObject](/docs/reference/engine/classes/GuiObject.md) has its
[TextScaled](/docs/reference/engine/classes/TextLabel.md) property set to true the text size
constrained by this property will scale dynamically with the container's
size. It will scale upwards with the GuiObject's size until the max size
is reached, at which point it will stay constant if the UI element
continues to grow.

### Property: UITextSizeConstraint.MinTextSize

```json
{
  "type": "int",
  "access": "ReadWrite",
  "security": {
    "read": "None",
    "write": "None"
  },
  "serialization": {
    "can_load": true,
    "can_save": true
  },
  "thread_safety": "ReadSafe",
  "category": "Behavior",
  "capabilities": [
    "UI"
  ]
}
```

This property indicated the smallest size in pixels the font is allowed to
be. This value defaults to 1 pixel and must be set less than or equal to
[UITextSizeConstraint.MaxTextSize](/docs/reference/engine/classes/UITextSizeConstraint.md).

If the affected [GuiObject](/docs/reference/engine/classes/GuiObject.md) has its
[TextScaled](/docs/reference/engine/classes/TextLabel.md) property set to true the text size
constrained by this property will scale dynamically with the container's
size. It will scale downwards with the GuiObject's size until the min size
is reached, at which point it will stay constant if the UI element
continues to shrink.

## Inherited Members

### From [Instance](/docs/reference/engine/classes/Instance.md)

- **Property `Archivable`** (`boolean`): Determines if an Instance and its descendants can be cloned using
- **Property `archivable`** (`boolean`):  *(deprecated, hidden)*
- **Property `Capabilities`** (`SecurityCapabilities`): The set of capabilities allowed to be used for scripts inside this
- **Property `Name`** (`string`): A non-unique identifier of the Instance.
- **Property `Parent`** (`Instance`): Determines the hierarchical parent of the Instance.
- **Property `PredictionMode`** (`PredictionMode`): 
- **Property `RobloxLocked`** (`boolean`): A deprecated property that used to protect CoreGui objects. *(hidden)*
- **Property `Sandboxed`** (`boolean`): When enabled, the instance can only access abilities in its `Capabilities`
- **Property `UniqueId`** (`UniqueId`): A unique identifier for the instance.
- **Method `AddTag(tag: string): ()`**: Applies a tag to the instance.
- **Method `children(): Instances`**: Returns an array of the object's children. *(deprecated)*
- **Method `ClearAllChildren(): ()`**: This method destroys all of an instance's children.
- **Method `Clone(): Instance`**: Create a copy of an instance and all its descendants, ignoring instances
- **Method `clone(): Instance`**:  *(deprecated)*
- **Method `Destroy(): ()`**: Sets the Instance.Parent property to `nil`, locks the
- **Method `destroy(): ()`**:  *(deprecated)*
- **Method `FindFirstAncestor(name: string): Instance?`**: Returns the first ancestor of the Instance whose
- **Method `FindFirstAncestorOfClass(className: string): Instance?`**: Returns the first ancestor of the Instance whose
- **Method `FindFirstAncestorWhichIsA(className: string): Instance?`**: Returns the first ancestor of the Instance for whom
- **Method `FindFirstChild(name: string, recursive?: boolean): Instance?`**: Returns the first child of the Instance found with the given name.
- **Method `findFirstChild(name: string, recursive?: boolean): Instance`**:  *(deprecated)*
- **Method `FindFirstChildOfClass(className: string): Instance?`**: Returns the first child of the Instance whose
- **Method `FindFirstChildWhichIsA(className: string, recursive?: boolean): Instance?`**: Returns the first child of the Instance for whom
- **Method `FindFirstDescendant(name: string): Instance?`**: Returns the first descendant found with the given Instance.Name.
- **Method `GetActor(): Actor?`**: Returns the Actor associated with the Instance, if any.
- **Method `GetAttribute(attribute: string): Variant`**: Returns the value which has been assigned to the given attribute name.
- **Method `GetAttributeChangedSignal(attribute: string): RBXScriptSignal`**: Returns an event that fires when the given attribute changes.
- **Method `GetAttributes(): Dictionary`**: Returns a dictionary of the instance's attributes.
- **Method `GetChildren(): Instances`**: Returns an array containing all of the instance's children.
- **Method `getChildren(): Instances`**:  *(deprecated)*
- **Method `GetDebugId(scopeLength?: int): string`**: Returns a coded string of the debug ID used internally by Roblox.
- **Method `GetDescendants(): Instances`**: Returns an array containing all of the descendants of the instance.
- **Method `GetFullName(): string`**: Returns a string describing the instance's ancestry.
- **Method `GetStyled(name: string, selector: string?): Variant`**: Returns the styled or explicitly modified value of the specified property,
- **Method `GetStyledPropertyChangedSignal(property: string): RBXScriptSignal`**: 
- **Method `GetTags(): Array`**: Gets an array of all tags applied to the instance.
- **Method `HasTag(tag: string): boolean`**: Check whether the instance has a given tag.
- **Method `IsAncestorOf(descendant: Instance): boolean`**: Returns true if an Instance is an ancestor of the given
- **Method `IsDescendantOf(ancestor: Instance): boolean`**: Returns `true` if an Instance is a descendant of the given
- **Method `isDescendantOf(ancestor: Instance): boolean`**:  *(deprecated)*
- **Method `IsPropertyModified(property: string): boolean`**: Returns `true` if the value stored in the specified property is not equal
- **Method `QueryDescendants(selector: string): Instances`**: 
- **Method `Remove(): ()`**: Sets the object's `Parent` to `nil`, and does the same for all its *(deprecated)*
- **Method `remove(): ()`**:  *(deprecated)*
- **Method `RemoveTag(tag: string): ()`**: Removes a tag from the instance.
- **Method `ResetPropertyToDefault(property: string): ()`**: Resets a property to its default value.
- **Method `SetAttribute(attribute: string, value: Variant): ()`**: Sets the attribute with the given name to the given value.
- **Method `WaitForChild(childName: string, timeOut: double): Instance`**: Returns the child of the Instance with the given name. If the
- **Event `AncestryChanged`**: Fires when the Instance.Parent property of this object or one of
- **Event `AttributeChanged`**: Fires whenever an attribute is changed on the Instance.
- **Event `ChildAdded`**: Fires after an object is parented to this Instance.
- **Event `childAdded`**:  *(deprecated)*
- **Event `ChildRemoved`**: Fires after a child is removed from this Instance.
- **Event `DescendantAdded`**: Fires after a descendant is added to the Instance.
- **Event `DescendantRemoving`**: Fires immediately before a descendant of the Instance is removed.
- **Event `Destroying`**: Fires immediately before (or is deferred until after) the instance is
- **Event `StyledPropertiesChanged`**: Fires whenever any style property is changed on the instance, including

### From [Object](/docs/reference/engine/classes/Object.md)

- **Property `ClassName`** (`string`): A read-only string representing the class this Object belongs to.
- **Property `className`** (`string`):  *(deprecated)*
- **Method `GetPropertyChangedSignal(property: string): RBXScriptSignal`**: Get an event that fires when a given property of the object changes.
- **Method `IsA(className: string): boolean`**: Returns true if an object's class matches or inherits from a given class.
- **Method `isA(className: string): boolean`**:  *(deprecated)*
- **Event `Changed`**: Fires immediately after a property of the object changes, with some