# Converting your shaders
Shaders written for the Built-in Render Pipeline are not compatible with the URP shaders.
For an overview of the mapping between built-in shaders and URP shaders, see [Shader mappings](#shader-mappings).
Use the [Render Pipeline Converter](features/rp-converter.md) to apply the shader mappings automatically.
**Note**: The Render Pipeline Converter makes irreversible changes to the project. Back up your project before the conversion.
**Tip**: If the preview thumbnails in the Project view are not shown correctly after the conversion, try right-clicking anywhere in the Project view and selecting **Reimport All**.
For [SpeedTree](https://docs.unity3d.com/Manual/SpeedTree.html) Shaders, Unity does not re-generate Materials when you re-import them, unless you click the **Generate Materials** or **Apply & Generate Materials** button.
## Custom shaders
You cannot upgrade Custom Unity shaders written for the Built-in Render Pipeline. Instead, custom shaders must be rewritten to work with URP or recreated in [ShaderGraph](https://docs.unity3d.com/Packages/com.unity.shadergraph@12.1/manual/index.html).
Any Materials in a Scene that use a custom shader when you upgrade a project to use URP turn pink to indicate the Material no longer works. To fix this, upgrade or change the Material's shader to one that is compatible with URP.
**Note**: URP does not support [Surface Shaders](https://docs.unity3d.com/Manual/SL-SurfaceShaders.html).
## Shader mappings
The following table shows which URP shaders the Built-in Render Pipeline shaders convert to when you use the Render Pipeline Converter.
| Unity built-in shader | Universal Render Pipeline shader |
| ------------------------------------------------- | ------------------------------------------- |
| Standard | Universal Render Pipeline/Lit |
| Standard (Specular Setup) | Universal Render Pipeline/Lit |
| Standard Terrain | Universal Render Pipeline/Terrain/Lit |
| Particles/Standard Surface | Universal Render Pipeline/Particles/Lit |
| Particles/Standard Unlit | Universal Render Pipeline/Particles/Unlit |
| Mobile/Diffuse | Universal Render Pipeline/Simple Lit |
| Mobile/Bumped Specular | Universal Render Pipeline/Simple Lit |
| Mobile/Bumped Specular(1 Directional Light) | Universal Render Pipeline/Simple Lit |
| Mobile/Unlit (Supports Lightmap) | Universal Render Pipeline/Simple Lit |
| Mobile/VertexLit | Universal Render Pipeline/Simple Lit |
| Legacy Shaders/Diffuse | Universal Render Pipeline/Simple Lit |
| Legacy Shaders/Specular | Universal Render Pipeline/Simple Lit |
| Legacy Shaders/Bumped Diffuse | Universal Render Pipeline/Simple Lit |
| Legacy Shaders/Bumped Specular | Universal Render Pipeline/Simple Lit |
| Legacy Shaders/Self-Illumin/Diffuse | Universal Render Pipeline/Simple Lit |
| Legacy Shaders/Self-Illumin/Bumped Diffuse | Universal Render Pipeline/Simple Lit |
| Legacy Shaders/Self-Illumin/Specular | Universal Render Pipeline/Simple Lit |
| Legacy Shaders/Self-Illumin/Bumped Specular | Universal Render Pipeline/Simple Lit |
| Legacy Shaders/Transparent/Diffuse | Universal Render Pipeline/Simple Lit |
| Legacy Shaders/Transparent/Specular | Universal Render Pipeline/Simple Lit |
| Legacy Shaders/Transparent/Bumped Diffuse | Universal Render Pipeline/Simple Lit |
| Legacy Shaders/Transparent/Bumped Specular | Universal Render Pipeline/Simple Lit |
| Legacy Shaders/Transparent/Cutout/Diffuse | Universal Render Pipeline/Simple Lit |
| Legacy Shaders/Transparent/Cutout/Specular | Universal Render Pipeline/Simple Lit |
| Legacy Shaders/Transparent/Cutout/Bumped Diffuse | Universal Render Pipeline/Simple Lit |
| Legacy Shaders/Transparent/Cutout/Bumped Specular | Universal Render Pipeline/Simple Lit |