remotion-dev/remotion · error · Error

Failed to create WebGL shader

Error message

Failed to create WebGL shader

What it means

Thrown by the drop-shadow runtime's compileShader helper when gl.createShader() returns null. Equivalent to the dot-grid case: the WebGL2 context could not allocate a shader object, almost always because the context is lost, destroyed, or resource-exhausted. The drop-shadow effect compiles four shaders (extract, horizontal blur, vertical blur, composite), so the first failing allocation throws.

Source

Thrown at packages/effects/src/drop-shadow/drop-shadow-runtime.ts:58

	readonly composite: {
		readonly uSource: WebGLUniformLocation | null;
		readonly uShadow: WebGLUniformLocation | null;
		readonly uOffset: WebGLUniformLocation | null;
		readonly uTexelSize: WebGLUniformLocation | null;
	};
	readonly colorCtx: CanvasRenderingContext2D;
	cachedColorStr: string;
	cachedColorRgba: ParsedColorRgba;
};

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(`Drop shadow shader compile failed: ${log ?? '(no log)'}`);
	}

	return shader;
};

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

View on GitHub (pinned to 78fe4bb3fd)

Solutions

1. Feature-detect WebGL2 before applying the effect: const gl = canvas.getContext('webgl2'); if (!gl) skip.
2. For headless rendering, launch Chrome with --use-gl=angle --use-angle=swiftshader (or the matching software renderer).
3. Reduce simultaneous drop-shadow instances; ensure cleanup runs to free shaders/programs.
4. Reload to recover from a lost context; update GPU drivers and browser.
5. File a Remotion issue if it reproduces on a freshly booted WebGL2-capable desktop browser.

const supportsWebGL2 = () => {
  try {
    return !!document.createElement('canvas').getContext('webgl2');
  } catch {
    return false;
  }
};

if (!supportsWebGL2()) {
  // omit the drop-shadow effect or render a CSS box-shadow fallback

try {
  state = setupDropShadow(canvas);
} catch (err) {
  if (err instanceof Error && /WebGL shader/i.test(err.message)) {
    console.error('Drop-shadow shader allocation failed:', err.message);
    // fall back to a CSS box-shadow layer
  } else {
    throw err;
  }
}

When it happens

Trigger: Lost WebGL2 context, exhausted shader limit, GPU memory pressure, or headless environment without GPU acceleration. Reached inside setupDropShadow() during initial shader compilation.

Common situations: Headless Chromium without software GL flags; long Studio sessions leaking shaders; GPU driver crash; many drop-shadow instances mounted; remote desktop / VM with passthrough GL.

Related errors

• Failed to create WebGL shader
• Failed to create WebGL program
• Failed to create WebGL texture
• Failed to create WebGL vertex array
• Failed to create WebGL buffer

AI-assisted analysis of remotion-dev/remotion@78fe4bb3fd (2026-08-12). Data as JSON: /api/errors/184ce24ac079636f. Report an issue: GitHub.