remotion-dev/remotion · error · TypeError

parameter 'diskSizeInMb' must not be NaN, but is

Error message

parameter 'diskSizeInMb' must not be NaN, but is

What it means

Second guard in validateDiskSizeInMb: after confirming the value is a number, it must not be NaN. NaN passes typeof === 'number' but represents an unparseable numeric, so this catches Number('abc')-style inputs that slipped past the type check.

Source

Thrown at packages/lambda-client/src/validate-disk-size-in-mb.ts:14

import {
	MAX_EPHEMERAL_STORAGE_IN_MB,
	MIN_EPHEMERAL_STORAGE_IN_MB,
} from './constants';

export const validateDiskSizeInMb = (diskSizeInMb: unknown) => {
	if (typeof diskSizeInMb !== 'number') {
		throw new TypeError(
			`parameter 'diskSizeInMb' must be a number, got a ${typeof diskSizeInMb}`,
		);
	}

	if (Number.isNaN(diskSizeInMb)) {
		throw new TypeError(`parameter 'diskSizeInMb' must not be NaN, but is`);
	}

	if (!Number.isFinite(diskSizeInMb)) {
		throw new TypeError(
			`parameter 'diskSizeInMb' must be finite, but is ${diskSizeInMb}`,
		);
	}

	if (
		diskSizeInMb < MIN_EPHEMERAL_STORAGE_IN_MB ||
		diskSizeInMb > MAX_EPHEMERAL_STORAGE_IN_MB
	) {
		throw new TypeError(
			`parameter 'diskSizeInMb' must be between ${MIN_EPHEMERAL_STORAGE_IN_MB} and ${MAX_EPHEMERAL_STORAGE_IN_MB}, but got ${diskSizeInMb}`,
		);
	}

	if (diskSizeInMb % 1 !== 0) {

View on GitHub (pinned to 78fe4bb3fd)

Solutions

1. Validate the source string parses cleanly with !Number.isNaN(Number(x)) before calling.
2. Provide a numeric default when the env var is absent.
3. Log the raw input value to find where NaN originates.

Example fix

// before
const disk = Number(readConfig().diskSize); // NaN if config missing/garbage
validateDiskSizeInMb(disk);

// after
const raw = readConfig().diskSize;
const disk = raw == null || Number.isNaN(Number(raw)) ? 2048 : Number(raw);
validateDiskSizeInMb(disk);

const disk = Number(diskSizeInMb);
if (Number.isNaN(disk)) {
  throw new TypeError(`diskSizeInMb is NaN; source value was ${diskSizeInMb}`);
}
validateDiskSizeInMb(disk);

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

When it happens

Trigger: Calling validateDiskSizeInMb with the literal NaN, or with Number(someUnparseableString) (e.g., Number('big-disk')) that yields NaN.

Common situations: Coercing a non-numeric env var with Number() and passing the NaN result; arithmetic on undefined producing NaN; JSON parse yielding NaN-shaped values.

Related errors

• parameter 'diskSizeInMb' must be a number, got a ${typeof di
• parameter 'diskSizeInMb' must be finite, but is ${diskSizeIn
• Disk size must be a positive integer. Received: ${diskSizeIn
• parameter 'diskSizeInMb' must be between ${MIN_EPHEMERAL_STO
• parameter 'diskSizeInMb' must be an integer but got ${diskSi

AI-assisted analysis of remotion-dev/remotion@78fe4bb3fd (2026-08-12). Data as JSON: /api/errors/7b88fa3867c94e26. Report an issue: GitHub.