slidevjs/slidev · error · Error

Invalid aspect ratio "${str}"

Error message

Invalid aspect ratio "${str}"

What it means

parseAspectRatio accepts a number, a numeric string, or a '<w><sep><h>' string where sep is one of the aspect-ratio separators. After splitting, both sides must be finite numbers and the height must be non-zero.

Source

Thrown at packages/parser/src/utils.ts:46

  }

  return uniq(indexes).filter(i => i <= total).sort((a, b) => a - b)
}

/**
 * Accepts `16/9` `1:1` `3x4`
 */
export function parseAspectRatio(str: string | number) {
  if (isNumber(str))
    return str
  if (!Number.isNaN(+str))
    return +str
  const [wStr = '', hStr = ''] = str.split(RE_ASPECT_RATIO_SEPARATOR)
  const w = Number.parseFloat(wStr.trim())
  const h = Number.parseFloat(hStr.trim())

  if (Number.isNaN(w) || Number.isNaN(h) || h === 0)
    throw new Error(`Invalid aspect ratio "${str}"`)

  return w / h
}

View on GitHub (pinned to 0d798ace58)

Solutions

1. Use one of the documented forms: 16/9, 1:1, 3x4, or a plain number like 1.7778
2. Ensure both sides are numeric and the second is non-zero
3. Use a recognized separator (/ : or x)

Example fix

// before
aspectRatio: 16_9
// after
aspectRatio: 16/9

function validAspectRatio(v: string | number): boolean {
  if (typeof v === 'number' || !Number.isNaN(+v)) return +v > 0
  const [w = '', h = ''] = String(v).split(/[\/:x]/)
  const wn = Number.parseFloat(w.trim()), hn = Number.parseFloat(h.trim())
  return Number.isFinite(wn) && Number.isFinite(hn) && hn !== 0
}

function isAspectRatioInput(v: unknown): v is string | number {
  return typeof v === 'number' || (typeof v === 'string' && /^\s*[\d.]+\s*[\/:x]\s*[\d.]+\s*$/.test(v))
}

When it happens

Trigger: Setting aspectRatio to a non-numeric string, an incomplete pair ('16/'), a zero height ('16/0'), or using an unsupported separator like underscore.

Common situations: Typos, unsupported separators, dividing by zero, pasting values like '16_9'.

Related errors

• [slidev] "prism" support has been dropped. Please use "highl
• Invalid timestamp format
• Invalid timestamp value: ${match[1]}
• Invalid timestamp unit: ${unit}
• Unknown timestamp remaining: ${remaining}

AI-assisted analysis of slidevjs/slidev@0d798ace58 (2026-08-12). Data as JSON: /api/errors/b75a1356ae6ba7b6. Report an issue: GitHub.