# commit() Submits the command buffer to run on the GPU. ``` func commit() ``` ## Discussion The [`commit()`](/documentation/Metal/MTLCommandBuffer/commit()) method sends the command buffer to the [`MTLCommandQueue`](/documentation/Metal/MTLCommandQueue) instance that owns it, which then schedules it to run on the GPU. If your app calls [`commit()`](/documentation/Metal/MTLCommandBuffer/commit()) for a command buffer that isn’t enqueued, the method effectively calls [`enqueue()`](/documentation/Metal/MTLCommandBuffer/enqueue()) for you. The [`commit()`](/documentation/Metal/MTLCommandBuffer/commit()) method has several restrictions, including: - You can commit a command buffer to its command queue only one time. - You can only commit a command buffer when it doesn’t have an active encoder (see [`MTLCommandBuffer`](/documentation/Metal/MTLCommandBuffer) and [`MTLCommandEncoder`](/documentation/Metal/MTLCommandEncoder)). - You can’t encode additional commands to a command buffer after you commit it. - You can’t call the [`addScheduledHandler(_:)`](/documentation/Metal/MTLCommandBuffer/addScheduledHandler(_:)) or [`addCompletedHandler(_:)`](/documentation/Metal/MTLCommandBuffer/addCompletedHandler(_:)) methods after you commit a command buffer. The GPU starts the command buffer after it starts any command buffers that are ahead of it in the same command queue. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)