remotion-dev/remotion · error · TypeError

endAt prop can not be NaN.

Error message

endAt prop can not be NaN.

What it means

validateStartFromProps rejects NaN for the deprecated endAt prop because NaN cannot represent a valid end frame and would silently break the stop-time calculation. Note: unlike startFrom/trimBefore, endAt allows Infinity is NOT checked here (only NaN is), but NaN is always invalid.

Solutions

1. Guard the parsed value with Number.isFinite() before passing it.
2. Fix the upstream string-to-number conversion (validate input format first).
3. Migrate to the non-deprecated trimAfter prop (same NaN rejection applies).
4. Omit the prop if the dynamic value cannot be guaranteed to be a valid number.

Example fix

// before
const endAt = Number(rawEnd); // NaN if rawEnd is non-numeric
<Video src={src} endAt={endAt} />
// after
const parsed = Number(rawEnd);
const endAt = Number.isFinite(parsed) ? parsed : undefined;
<Video src={src} trimAfter={endAt} />

if (endAt !== undefined && Number.isNaN(endAt)) {
  throw new Error('endAt must not be NaN');
}

const isValidEndAt = (v: unknown): v is number =>
  typeof v === 'number' && !Number.isNaN(v);

When it happens

Trigger: Passing endAt={NaN}, typically the result of Number('abc'), an undefined arithmetic result, or parseFloat on a non-numeric string.

Common situations: Parsing an end timestamp from user input or a CMS with Number()/parseFloat() that yields NaN; computing endAt from a duration that is itself undefined.

Related errors

• startFrom prop can not be NaN or Infinity.
• Cannot use both endAt and trimAfter props. Use trimAfter…
• Cannot use both startFrom and trimBefore props. Use…
• endAt must be a positive number, instead got
• endAt prop must be greater than startFrom prop.

AI-assisted analysis of remotion-dev/remotion@78fe4bb3fd (2026-08-12). Data as JSON: /api/errors/aa07210fe32e8ae9. Report an issue: GitHub.

Appendix: source

Thrown at packages/core/src/validate-start-from-props.ts:31

			throw new TypeError('startFrom prop can not be NaN or Infinity.');
		}

		if (startFrom < 0) {
			throw new TypeError(
				`startFrom must be greater than equal to 0 instead got ${startFrom}.`,
			);
		}
	}

	if (typeof endAt !== 'undefined') {
		if (typeof endAt !== 'number') {
			throw new TypeError(
				`type of endAt prop must be a number, instead got type ${typeof endAt}.`,
			);
		}

		if (isNaN(endAt)) {
			throw new TypeError('endAt prop can not be NaN.');
		}

		if (endAt <= 0) {
			throw new TypeError(
				`endAt must be a positive number, instead got ${endAt}.`,
			);
		}
	}

	if ((endAt as number) < (startFrom as number)) {
		throw new TypeError('endAt prop must be greater than startFrom prop.');
	}
};

export const validateTrimProps = (
	trimBefore: number | undefined,
	trimAfter: number | undefined,
) => {

View on GitHub (pinned to 78fe4bb3fd)