remotion-dev/remotion · error · TypeError

random() takes only one argument

Error message

random() takes only one argument

What it means

random(seed, dummy?) declares a second parameter only to detect old/mistaken calling conventions. If `dummy !== undefined` it throws immediately, catching callers who thought random() took a range (e.g. random(seed, max)). The function takes exactly one seed.

Source

Thrown at packages/core/src/random.ts:30

	for (i = 0; i < str.length; i++) {
		chr = str.charCodeAt(i);
		hash = (hash << 5) - hash + chr;
		hash |= 0; // Convert to 32bit integer
	}

	return hash;
}

export type RandomSeed = number | string | null;

/*
 * @description A deterministic pseudo-random number generator. Pass in the same seed and get the same pseudorandom number.
 * @see [Documentation](https://www.remotion.dev/docs/random)
 */
export const random = (seed: RandomSeed, dummy?: unknown) => {
	if (dummy !== undefined) {
		throw new TypeError('random() takes only one argument');
	}

	if (seed === null) {
		return Math.random();
	}

	if (typeof seed === 'string') {
		return mulberry32(hashCode(seed));
	}

	if (typeof seed === 'number') {
		return mulberry32(seed * 10000000000);
	}

	throw new Error('random() argument must be a number or a string');
};

View on GitHub (pinned to 78fe4bb3fd)

Solutions

1. Remove the second argument: random(seed).
2. Scale the result yourself: random(seed) * (max - min) + min.

Example fix

// before
const v = random(seed, 100);
// after
const v = random(seed) * 100;

const v = random(seed); // never pass a second argument

// TypeScript already enforces (seed, dummy?: unknown); for JS:
const callRandom = (seed: RandomSeed) => random(seed);

When it happens

Trigger: Calling random(seed, 100), random(seed, min, max), or any form passing a second positional argument.

Common situations: Copy-pasting from a tutorial or library that used a different/older random API expecting a range argument.

Related errors

• random() argument must be a number or a string
• "samples" must be >= 1, but got ${samples}
• "${name}" must be a [number, number] tuple
• "${name}" must be a [number, number] tuple
• "${name}" must be greater than 0, but got ${JSON.stringify(v

AI-assisted analysis of remotion-dev/remotion@78fe4bb3fd (2026-08-12). Data as JSON: /api/errors/b5ae2213fe9d5b8c. Report an issue: GitHub.