remotion-dev/remotion · error · Error

"fps" must not be NaN, but got ${fps} ${location}

Error message

"fps" must not be NaN, but got ${fps} ${location}

What it means

Even though `Number.isFinite(NaN)` is `false` and would be caught by the earlier `!Number.isFinite` check in practice, this branch exists as a defensive explicit NaN guard inside `validateFps()`. It signals that the caller passed `NaN` as the frame rate.

Source

Thrown at packages/core/src/validation/validate-fps.ts:19

export function validateFps(
	fps: unknown,
	location: string,
	isGif: boolean,
): asserts fps is number {
	if (typeof fps !== 'number') {
		throw new Error(
			`"fps" must be a number, but you passed a value of type ${typeof fps} ${location}`,
		);
	}

	if (!Number.isFinite(fps)) {
		throw new Error(
			`"fps" must be a finite, but you passed ${fps} ${location}`,
		);
	}

	if (isNaN(fps)) {
		throw new Error(`"fps" must not be NaN, but got ${fps} ${location}`);
	}

	if (fps <= 0) {
		throw new TypeError(`"fps" must be positive, but got ${fps} ${location}`);
	}

	if (isGif && fps > 50) {
		throw new TypeError(
			`The FPS for a GIF cannot be higher than 50. Use the --every-nth-frame option to lower the FPS: https://remotion.dev/docs/render-as-gif`,
		);
	}
}

View on GitHub (pinned to 78fe4bb3fd)

Solutions

1. Replace the `NaN` source with a concrete number.
2. Guard the input: `const fps = Number.isNaN(raw) ? 30 : raw;`.
3. Trace upstream: log the value just before it is passed to find where `NaN` originates.

Example fix

// before
const fps = parseInt(userInput.fps); // NaN when empty
<Composition fps={fps} ... />
// after
const fps = Number.parseInt(userInput.fps, 10);
<Composition fps={Number.isNaN(fps) ? 30 : fps} ... />

const fps = Number.isNaN(rawFps) ? 30 : rawFps;

const isValidFps = (v: unknown): v is number => typeof v === 'number' && Number.isFinite(v) && !Number.isNaN(v) && v > 0;

When it happens

Trigger: Passing `fps={NaN}` to a composition, or a value derived from `parseInt(undefined)`, `Number(undefined)`, or `0/0`.

Common situations: Parsing form input where the field is empty (`Number('')` is `0`, but `parseInt(undefined)` is `NaN`), or arithmetic on `undefined` numerics.

Related errors

• "fps" must be a finite, but you passed ${fps} ${location}
• "fps" must be positive, but got ${fps} ${location}
• "fps" must be a number, but you passed a value of type ${typ
• A "duration" of a spring is NaN, which it must not be
• Argument passed to "${api}" for param "${param}" is ${JSON.s

AI-assisted analysis of remotion-dev/remotion@78fe4bb3fd (2026-08-12). Data as JSON: /api/errors/7a3c30b02a5745d7. Report an issue: GitHub.