Unity 6.3 LTS — Deprecated APIs

Last verified: 2026-02-13

Quick lookup table for deprecated APIs and their replacements. Format: Don't use X → Use Y instead

Input

Deprecated	Replacement	Notes
`Input.GetKey()`	`Keyboard.current[Key.X].isPressed`	New Input System
`Input.GetKeyDown()`	`Keyboard.current[Key.X].wasPressedThisFrame`	New Input System
`Input.GetMouseButton()`	`Mouse.current.leftButton.isPressed`	New Input System
`Input.GetAxis()`	`InputAction` callbacks	New Input System
`Input.mousePosition`	`Mouse.current.position.ReadValue()`	New Input System

Migration: Install com.unity.inputsystem package.

UI

Deprecated	Replacement	Notes
`Canvas` (UGUI)	`UIDocument` (UI Toolkit)	UI Toolkit is now production-ready
`Text` component	`TextMeshPro` or UI Toolkit `Label`	Better rendering, fewer draw calls
`Image` component	UI Toolkit `VisualElement` with background	More flexible styling

Migration: UGUI still works, but UI Toolkit is recommended for new projects.

DOTS/Entities

Deprecated	Replacement	Notes
`ComponentSystem`	`ISystem` (unmanaged)	Entities 1.0+ complete rewrite
`JobComponentSystem`	`ISystem` with `IJobEntity`	Burst-compatible
`GameObjectEntity`	Pure ECS workflow	No GameObject conversion
`EntityManager.CreateEntity()` (old signature)	`EntityManager.CreateEntity(EntityArchetype)`	Explicit archetype
`ComponentDataFromEntity<T>`	`ComponentLookup<T>`	Entities 1.0+ rename

Migration: See Entities package migration guide. Major refactor required.

Rendering

Deprecated	Replacement	Notes
`CommandBuffer.DrawMesh()`	RenderGraph API	URP/HDRP render passes
`OnPreRender()` / `OnPostRender()`	`RenderPipelineManager` callbacks	SRP compatibility
`Camera.SetReplacementShader()`	Custom render pass	Not supported in SRP

Physics

Deprecated	Replacement	Notes
`Physics.RaycastAll()`	`Physics.RaycastNonAlloc()`	Avoid GC allocations
`Rigidbody.velocity` (direct write)	`Rigidbody.AddForce()`	Better physics stability

Asset Loading

Deprecated	Replacement	Notes
`Resources.Load()`	Addressables	Better memory control, async loading
Synchronous asset loading	`Addressables.LoadAssetAsync()`	Non-blocking

Animation

Deprecated	Replacement	Notes
Legacy Animation component	Animator Controller	Mecanim system
`Animation.Play()`	`Animator.Play()`	State machine control

Particles

Deprecated	Replacement	Notes
Legacy Particle System	Visual Effect Graph	GPU-accelerated, more performant

Scripting

Deprecated	Replacement	Notes
`WWW` class	`UnityWebRequest`	Modern async networking
`Application.LoadLevel()`	`SceneManager.LoadScene()`	Scene management

Platform-Specific

WebGL

Deprecated	Replacement	Notes
WebGL 1.0	WebGL 2.0 or WebGPU	Unity 6+ defaults to WebGPU

Quick Migration Patterns

Input Example

// ❌ Deprecated
if (Input.GetKeyDown(KeyCode.Space)) {
    Jump();
}

// ✅ New Input System
using UnityEngine.InputSystem;
if (Keyboard.current.spaceKey.wasPressedThisFrame) {
    Jump();
}

Asset Loading Example

// ❌ Deprecated
var prefab = Resources.Load<GameObject>("Enemies/Goblin");

// ✅ Addressables
var handle = Addressables.LoadAssetAsync<GameObject>("Enemies/Goblin");
await handle.Task;
var prefab = handle.Result;

UI Example

// ❌ Deprecated (UGUI)
GetComponent<Text>().text = "Score: 100";

// ✅ TextMeshPro
GetComponent<TextMeshProUGUI>().text = "Score: 100";

// ✅ UI Toolkit
rootVisualElement.Q<Label>("score-label").text = "Score: 100";

Sources: