remotion-dev/remotion · error · Error

"${name}" must be an object, an array was passed ${compositi

Error message

"${name}" must be an object, an array was passed ${compositionId ? `for composition "${compositionId}"` : ''}

What it means

After confirming `defaultProps`/`inputProps` is an object type, `validateDefaultAndInputProps` additionally rejects arrays. Props must be a keyed object; an array is a common `typeof === 'object'` value that is not a valid props bag. The message includes the composition id when available.

Source

Thrown at packages/core/src/validation/validate-default-props.ts:17

export const validateDefaultAndInputProps = (
	defaultProps: unknown,
	name: 'defaultProps' | 'inputProps',
	compositionId: string | null,
) => {
	if (!defaultProps) {
		return;
	}

	if (typeof defaultProps !== 'object') {
		throw new Error(
			`"${name}" must be an object, but you passed a value of type ${typeof defaultProps}`,
		);
	}

	if (Array.isArray(defaultProps)) {
		throw new Error(
			`"${name}" must be an object, an array was passed ${
				compositionId ? `for composition "${compositionId}"` : ''
			}`,
		);
	}
};

View on GitHub (pinned to 78fe4bb3fd)

Solutions

1. Wrap the array under a key: `defaultProps={{items: [...]}}`.
2. If the JSON root is an array, pick a single element or restructure into an object.
3. Confirm the shape with `Array.isArray()` before assigning.

Example fix

// before
const data = require('./props.json'); // data === [{...}, {...}]
<Composition defaultProps={data} ... />
// after
const data = require('./props.json');
<Composition defaultProps={{items: data}} ... />

if (Array.isArray(props)) {
  throw new Error('props must be an object, not an array');
}

const isPropsObject = (p) => p == null || (typeof p === 'object' && !Array.isArray(p));

When it happens

Trigger: Passing `defaultProps={[...]}` or `inputProps={[...]}` (an Array) to a `<Composition>`. Common when props originate from a JSON file that is a top-level array, or when spreading a list by mistake.

Common situations: Loading props from a JSON file whose root is an array; converting a list of items into props and forgetting to wrap under a key; mapping over data and passing the resulting array directly.

Related errors

• "${name}" must be an object, but you passed a value of type
• No composition with the ID "${compId}" found.
• No id for composition passed.
• Multiple composition with id ${comp.id} are registered.
• Could not serialize the passed input props to JSON: ${(err a

AI-assisted analysis of remotion-dev/remotion@78fe4bb3fd (2026-08-12). Data as JSON: /api/errors/19ad4e1fbe64e7d8. Report an issue: GitHub.