WebGPU Developer Features

François Beaufort

Published: Jun 3, 2025

Chrome's WebGPU API implementation includes features intended solely for development and testing. These features are outside the standard WebGPU specification and must not be used in production.

This document details how to enable WebGPU developer features and provides a comprehensive list.

Prerequisite

To enable WebGPU developer features in Chrome, follow these steps:

1. Enable the "WebGPU Developer Features" flag at chrome://flags/#enable-webgpu-developer-features.
2. Restart Chrome browser.

Disable timestamp queries quantization

Timestamp queries enable WebGPU applications to accurately measure (to the nanosecond) the execution time of GPU commands during compute and render passes. These queries are essential for analyzing GPU workload performance and behavior. For more details, refer to Timestamp queries in compute and render passes.

Due to timing attack concerns, timestamp queries are quantized with a resolution of 100 microseconds, which provides a good compromise between precision and security. This quantization is automatically disabled when the "WebGPU Developer Features" flag is enabled.

Extended adapter information

To get a deeper understanding of the adapter being used, GPUAdapterInfo exposes the following attributes:

• The device attribute (standardized) is a vendor-specific adapter identifier.
• The description attribute (standardized) is a human-readable string providing adapter details.
• The driver attribute (non-standardized) is a human-readable string describing the driver.
• The backend attribute (non-standardized) indicates the graphics backend, such as "WebGPU", "D3D11", "D3D12", "metal", "vulkan", "openGL", "openGLES", or "null".
• The type attribute (non-standardized) identifies the GPU type: "discrete GPU", "integrated GPU", "CPU", or "unknown".
• The d3dShaderModel attribute (non-standardized) specifies the maximum supported D3D shader model number, for example, 62 indicates HLSL SM 6.2 support.
• The vkDriverVersion attribute (non-standardized) is the vendor-specified Vulkan driver version.
• The powerPreference attribute (non-standardized) is "low-power" or "high-performance", based on the GPUPowerPreference in GPURequestAdapterOptions.

To anticipate memory limitations when allocating large amounts during the development of your app, GPUAdapterInfo exposes memoryHeaps non-standardized information such as the size and type of memory heaps available on the adapter.

const adapter = await navigator.gpu.requestAdapter();

for (const { size, properties } of adapter.info.memoryHeaps) {
  console.log(size); // memory heap size in bytes
  if (properties & GPUHeapProperty.DEVICE_LOCAL)  { /* ... */ }
  if (properties & GPUHeapProperty.HOST_VISIBLE)  { /* ... */ }
  if (properties & GPUHeapProperty.HOST_COHERENT) { /* ... */ }
  if (properties & GPUHeapProperty.HOST_UNCACHED) { /* ... */ }
  if (properties & GPUHeapProperty.HOST_CACHED)   { /* ... */ }
}

Shader module compilation option strict math

The GPUShaderModuleDescriptor includes a strictMath non-standardized boolean option, which enables or disables strict mathematical precision during shader module compilation. This option is supported on Metal and Direct3D. When strictMath is enabled, the compiler adheres to precise mathematical rules. Conversely, disabling it allows the compiler to optimize shaders by:

• Ignoring the possibility of NaN and Infinity values.
• Treating -0 as +0.
• Replacing division with faster multiplication by the reciprocal.
• Rearranging operations based on associative and distributive properties.

const adapter = await navigator.gpu.requestAdapter();
const device = await adapter.requestDevice();

const code = `
  // Examines the bit pattern of the floating-point number to
  // determine if it represents a NaN according to the IEEE 754 standard.
  fn isNan(x : f32) -> bool {
    bool ones_exp = (bitcast<u32>(x) & 0x7f8) == 0x7f8;
    bool non_zero_sig = (bitcast<u32>(x) & 0x7ffff) != 0;
    return ones_exp && non_zero_sig;
  }
  // ...
`;

// Enable strict math during shader compilation.
const shaderModule = device.createShaderModule({ code, strictMath: true });

Import video with zero-copy

The GPUExternalTexture isZeroCopy non-standardized boolean attribute lets you know whether the video imported with importExternalTexture() was directly accessed by the GPU without the need for an intermediate copy.

const adapter = await navigator.gpu.requestAdapter();
const device = await adapter.requestDevice();

const video = document.querySelector('video');
const externalTexture = device.importExternalTexture({ source: video });

if (externalTexture.isZeroCopy) {
  console.log('Video frame was accessed directly by` the GPU');
}