remotion-dev/remotion · error · Error

${path}.confidence must be between 0 and 1.

Error message

${path}.confidence must be between 0 and 1.

What it means

parseCaptionFile requires that when a caption's confidence is a number, it lies between 0 and 1 inclusive. Values outside that range (e.g. percentages like 95 instead of 0.95) are rejected with the offending caption's index path.

Source

Thrown at packages/studio/src/components/parse-caption-file.ts:70

		}

		if (caption.endMs < caption.startMs) {
			throw new Error(`${path}.endMs must not be earlier than startMs.`);
		}

		if (caption.timestampMs !== null && !isFiniteNumber(caption.timestampMs)) {
			throw new Error(`${path}.timestampMs must be a finite number or null.`);
		}

		if (caption.confidence !== null && !isFiniteNumber(caption.confidence)) {
			throw new Error(`${path}.confidence must be a finite number or null.`);
		}

		if (
			typeof caption.confidence === 'number' &&
			(caption.confidence < 0 || caption.confidence > 1)
		) {
			throw new Error(`${path}.confidence must be between 0 and 1.`);
		}

		if (
			caption.pageBreakAfter !== undefined &&
			typeof caption.pageBreakAfter !== 'boolean'
		) {
			throw new Error(
				`${path}.pageBreakAfter must be a boolean when provided.`,
			);
		}

		if (previousStart !== null && caption.startMs < previousStart) {
			throw new Error(`${path}.startMs is out of timestamp order.`);
		}

		previousStart = caption.startMs;
	}

View on GitHub (pinned to b2f4e34732)

Solutions

1. Divide percentage values by 100: 95 -> 0.95
2. Clamp confidence to [0, 1] in the export script
3. Set confidence to null if the scale is unknown

Example fix

// before
{"text": "hi", "startMs": 0, "endMs": 1000, "confidence": 95}
// after
{"text": "hi", "startMs": 0, "endMs": 1000, "confidence": 0.95}

for (const [i, c] of parsed.entries()) {
  const conf = (c as any).confidence;
  if (typeof conf === 'number' && (conf < 0 || conf > 1)) {
    throw new Error(`captions[${i}].confidence must be between 0 and 1`);
  }
}

const isUnitInterval = (v: unknown): v is number =>
  typeof v === 'number' && Number.isFinite(v) && v >= 0 && v <= 1;

try {
  const captions = parseCaptionFile({fileName, contents});
} catch (e) {
  // divide percentages by 100 and retry
}

When it happens

Trigger: captions[i].confidence is 95 (a percentage) or 1.5 — the parse succeeded as a number but fails the 0..1 range check.

Common situations: ASR exports using 0-100 percentage scale; multiplying a probability twice; manual entry of percent values.

Understand the failure class

Background: "value must be between 0 and 1" / "out of range" / "must not be negative" errors: fixing range-validation failures across open-source libraries — this error's family across 42 libraries.

Related errors

• Expected a Remotion Caption[] JSON array.
• ${path} must be an object.
• ${path}.text must be a string.
• ${path}.startMs must be a finite, non-negative number.
• ${path}.endMs must be a finite, non-negative number.

AI-assisted analysis of remotion-dev/remotion@b2f4e34732 (2026-09-09). Data as JSON: /api/errors/70376004b9f235d9. Report an issue: GitHub.