files/en-us/web/api/gpubuffer/usage/index.md
{{APIRef("WebGPU API")}}{{SecureContext_Header}}{{AvailableInWorkers}}
The usage read-only property of the
{{domxref("GPUBuffer")}} interface contains the {{glossary("bitwise flags")}} representing the allowed usages of the GPUBuffer.
usage is set via the usage property in the descriptor object passed into the originating {{domxref("GPUDevice.createBuffer()")}} call.
The bitwise flags representing the original usages set when the GPUBuffer was first created. The returned number is the sum of decimal values representing the different flags, as seen in the table below.
| Bitwise flag | Usage description | Hex equiv. | Decimal equiv. |
|---|---|---|---|
GPUBufferUsage.COPY_SRC | The buffer can be used as the source of a copy operation, for example the source argument of a {{domxref("GPUCommandEncoder.copyBufferToBuffer","copyBufferToBuffer()")}} call. | 0x0004 | 4 |
GPUBufferUsage.COPY_DST | The buffer can be used as the destination of a copy/write operation, for example the destination argument of a {{domxref("GPUCommandEncoder.copyTextureToBuffer", "copyTextureToBuffer()")}} call. | 0x0008 | 8 |
GPUBufferUsage.INDEX | The buffer can be used as an index buffer, for example as the buffer argument passed to {{domxref("GPURenderPassEncoder.setIndexBuffer", "setIndexBuffer()")}}. | 0x0010 | 16 |
GPUBufferUsage.INDIRECT | The buffer can be used to store indirect command arguments, for example as the indirectBuffer argument of a {{domxref("GPURenderPassEncoder.drawIndirect", "drawIndirect()")}} or {{domxref("GPUComputePassEncoder.dispatchWorkgroupsIndirect", "dispatchWorkgroupsIndirect()")}} call. | 0x0100 | 256 |
GPUBufferUsage.MAP_READ | The buffer can be mapped for reading, for example when calling {{domxref("GPUBuffer.mapAsync", "mapAsync()")}} with a mode of GPUMapMode.READ. This flag may only be combined with GPUBufferUsage.COPY_DST. | 0x0001 | 1 |
GPUBufferUsage.MAP_WRITE | The buffer can be mapped for writing, for example when calling {{domxref("GPUBuffer.mapAsync", "mapAsync()")}} with a mode of GPUMapMode.WRITE. This flag may only be combined with GPUBufferUsage.COPY_SRC. | 0x0002 | 2 |
GPUBufferUsage.QUERY_RESOLVE | The buffer can be used to capture query results, for example as the destination argument of a {{domxref("GPUCommandEncoder.resolveQuerySet", "resolveQuerySet()")}} call. | 0x0200 | 512 |
GPUBufferUsage.STORAGE | The buffer can be used as a storage buffer, for example as a resource in a bind group entry when creating a {{domxref("GPUBindGroup")}} (via {{domxref("GPUDevice.createBindGroup", "createBindGroup()")}}), which adheres to a {{domxref("GPUBindGroupLayout")}} entry with a buffer binding layout type of "storage" or "read-only-storage". | 0x0080 | 128 |
GPUBufferUsage.UNIFORM | The buffer can be used as a uniform buffer, for example as a resource in a bind group entry when creating a {{domxref("GPUBindGroup")}} (via {{domxref("GPUDevice.createBindGroup", "createBindGroup()")}}), which adheres to a {{domxref("GPUBindGroupLayout")}} entry with a buffer binding layout type of "uniform". | 0x0040 | 64 |
GPUBufferUsage.VERTEX | The buffer can be used as a vertex buffer, for example as the buffer argument passed to {{domxref("GPURenderPassEncoder.setVertexBuffer", "setVertexBuffer()")}}. | 0x0020 | 32 |
const output = device.createBuffer({
size: BUFFER_SIZE,
usage: GPUBufferUsage.STORAGE | GPUBufferUsage.COPY_SRC,
});
console.log(output.usage); // 132
const stagingBuffer = device.createBuffer({
size: BUFFER_SIZE,
usage: GPUBufferUsage.MAP_READ | GPUBufferUsage.COPY_DST,
});
console.log(stagingBuffer.usage); // 9
{{Specifications}}
{{Compat}}