WebGPU Video Filters: Real-time 4K Processing in JS

In 2026, web-based video editors (like the new version of MojoDocs Video) are competing with native apps on performance. The secret weapon? WebGPU.

Before WebGPU, we used CSS filters or WebGL. But for 4K video at 60fps, those APIs often result in dropped frames or high battery drain.

The Power of Compute Shaders

While WebGL is focused on the "Render Pipeline," WebGPU gives us access to "Compute Pipelines." This allows us to process every pixel of a video frame in parallel with massive efficiency.

Integrating with WebCodecs

The real power comes from combining WebCodecs (for decoding) with WebGPU (for processing).

javascript
// 1. Get the frame from VideoTrack
const reader = trackProcessor.readable.getReader();
const { value: videoFrame } = await reader.read();

// 2. Import into WebGPU
const texture = device.importExternalTexture({
  source: videoFrame
});

// 3. Run Compute Shader
const passEncoder = commandEncoder.beginComputePass();
passEncoder.setPipeline(filterPipeline);
passEncoder.setBindGroup(0, device.createBindGroup({
  layout: filterPipeline.getBindGroupLayout(0),
  entries: [{ binding: 0, resource: texture }]
}));
passEncoder.dispatchWorkgroups(Math.ceil(width / 8), Math.ceil(height / 8));
passEncoder.end();

Complex Filters: Bokeh and Color Grading

With compute shaders, filters that were once "impossible" in the browser are now instant:

• Box Blur & Bokeh: Multi-pass algorithms that used to take seconds now take milliseconds.
• LUTs (Look Up Tables): High-fidelity color grading without any CPU overhead.
• AI Upscaling: Running small super-resolution models directly on the frame.

Conclusion

We are entering a golden age of web media. With WebGPU, the browser is no longer a secondary platform for creative tools; it is the primary one.