Metal is a low-level, low-overhead hardware-accelerated 3D graphic and compute shader API created by Apple, debuting in iOS 8.

It is intended to improve performance by offering low-level access to the GPU hardware for apps on iOS, iPadOS, macOS, and tvOS.

Metal uses a specific shading language based on C++14, implemented using Clang and LLVM.

[8] Metal Performance Shaders is a highly optimized library of graphics functions that can help application developers achieve great performance at the same time decrease work on maintaining GPU family specific functions.

[11] On June 5, 2017, at WWDC, Apple announced the second version of Metal, to be supported by macOS High Sierra, iOS 11 and tvOS 11.

Metal 2 enables more efficient profiling and debugging in Xcode, accelerated machine learning, lower CPU workload, support for virtual reality on macOS, and specificities of the Apple A11 GPU, in particular.