What causes "Failed to create WebGL shader" in remotion-dev/remotion?

Check gl.isContextLost() and restart the render if true.

remotion-dev/remotion · error · Error

Failed to create WebGL shader

Error message

Failed to create WebGL shader

What it means

Thrown by the compileShader() helper of the halftone WebGL2 effect when gl.createShader(type) returns null. A null shader means the GL implementation refused to allocate a shader object — object-budget exhaustion or context loss — before any source is even attached. The effect has not yet attempted to compile, so no info log exists.

Source

Thrown at packages/effects/src/halftone.ts:357

	colorCtx: CanvasRenderingContext2D;
	cachedColorStr: string;
	cachedColorRgba: ParsedColorRgba;
};

const SHAPE_INDEX: Record<HalftoneShape, number> = {
	circle: 0,
	square: 1,
	line: 2,
};

const compileShader = (
	gl: WebGL2RenderingContext,
	type: number,
	source: string,
): WebGLShader => {
	const shader = gl.createShader(type);
	if (!shader) {
		throw new Error('Failed to create WebGL shader');
	}

	gl.shaderSource(shader, source);
	gl.compileShader(shader);
	if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
		const log = gl.getShaderInfoLog(shader);
		gl.deleteShader(shader);
		throw new Error(`Halftone shader compile failed: ${log ?? '(no log)'}`);
	}

	return shader;
};

const linkProgram = (
	gl: WebGL2RenderingContext,
	vs: WebGLShader,
	fs: WebGLShader,
): WebGLProgram => {

View on GitHub (pinned to 78fe4bb3fd)

Solutions

Check gl.isContextLost() and restart the render if true.
Reduce the number of WebGL2 effects in flight per render.
Render on a machine with a healthier GPU/driver.
Restart Chrome/Studio to clear leaked GL objects.

Defensive patterns

Strategy: try-catch

Validate before calling

// Probe whether the context will allocate a shader object.
function canCreateShader(canvas: HTMLCanvasElement): boolean {
  const gl = canvas.getContext('webgl2');
  if (!gl) return false;
  const s = gl.createShader(gl.VERTEX_SHADER);
  const ok = s !== null;
  if (s) gl.deleteShader(s);
  return ok;
}

Try / catch

try {
  // ...use halftone()
} catch (e) {
  if (e instanceof Error && /Failed to create WebGL shader/.test(e.message)) {
    // shader object budget exhausted or context lost; restart render
  } else throw e;
}

Prevention

Keep concurrent WebGL2 effect count within the GPU's shader object budget.
Watch for context-loss events and restart the worker.
Reuse effect state across frames instead of re-creating shaders each frame.

When it happens

Trigger: setup() of the halftone effect running when the GL context is lost or its shader object budget is exhausted; rendering on a GPU/driver whose shader object limit is unusually low.

Common situations: Long render sessions allocating many WebGL2 effects; GPU process crash leaving a zombie context; integrated GPUs under heavy load.

Related errors

AI-assisted analysis of remotion-dev/remotion@78fe4bb3fd (2026-08-12). Data as JSON: /api/errors/65f6368efb48804b. Report an issue: GitHub.