remotion-dev/remotion · error · TypeError

The "trimBefore" prop of <Sequence /> must be a real number,

Error message

The "trimBefore" prop of <Sequence /> must be a real number, but it is NaN.

What it means

Thrown when trimBefore is the literal NaN. Because the prior check (trimBefore < 0) is false for NaN, this guard catches the case explicitly before the finite check. Passing NaN corrupts frame math silently, so it is rejected.

Source

Thrown at packages/core/src/Sequence.tsx:243

		throw new TypeError(
			`The "from" prop of a sequence must be finite, but got ${from}.`,
		);
	}

	if (typeof trimBefore !== 'number') {
		throw new TypeError(
			`You passed to the "trimBefore" prop of your <Sequence> an argument of type ${typeof trimBefore}, but it must be a number.`,
		);
	}

	if (trimBefore < 0) {
		throw new TypeError(
			`The "trimBefore" prop of <Sequence /> must be greater than or equal to 0, but got ${trimBefore}.`,
		);
	}

	if (Number.isNaN(trimBefore)) {
		throw new TypeError(
			'The "trimBefore" prop of <Sequence /> must be a real number, but it is NaN.',
		);
	}

	if (!Number.isFinite(trimBefore)) {
		throw new TypeError(
			`The "trimBefore" prop of <Sequence /> must be finite, but it is ${trimBefore}.`,
		);
	}

	if (typeof freeze !== 'undefined' && freeze !== null) {
		if (typeof freeze !== 'number') {
			throw new TypeError(
				`The "freeze" prop of <Sequence /> must be a number, but is of type ${typeof freeze}.`,
			);
		}

		if (Number.isNaN(freeze)) {

View on GitHub (pinned to 78fe4bb3fd)

Solutions

1. Use Number.isFinite(trimBefore) before passing the prop.
2. Fall back to a default when parsing fails: const tb = Number(raw); if (!Number.isFinite(tb)) tb = 0.
3. Validate upstream data shape at the config loader.

Example fix

// before
const trimBefore = parseInt(config.trim, 10);
<Sequence trimBefore={trimBefore} />

// after
const trimBefore = Number(config.trim);
<Sequence trimBefore={Number.isFinite(trimBefore) ? trimBefore : 0} />

if (!Number.isFinite(trimBefore)) {
  trimBefore = 0;
}

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

When it happens

Trigger: trimBefore is the result of Number(undefined), parseInt(nonNumericString), 0/0, or Math.sqrt(-1).

Common situations: Parsing a missing or malformed trimBefore field from config; arithmetic on undefined variables; parseFloat returning NaN on empty strings.

Related errors

• The layout prop of <Sequence /> expects either "absolute-fil
• The cropLeft, cropRight, cropTop and cropBottom props of <Se
• If layout="none", you may not pass a style. Passed: ${JSON.s
• You passed to durationInFrames an argument of type ${typeof
• You passed to the "from" props of your <Sequence> an argumen

AI-assisted analysis of remotion-dev/remotion@78fe4bb3fd (2026-08-12). Data as JSON: /api/errors/612b0398ea74f0a8. Report an issue: GitHub.