What causes "Failed to parse HTML string" in ueberdosis/tiptap?

Failed to parse HTML string

Error message

Failed to parse HTML string

What it means

Error "Failed to parse HTML string" thrown in ueberdosis/tiptap.

Source

Thrown at packages/html/src/generateJSON.ts:33

 * const json = generateJSON(html, extensions)
 * console.log(json) // { type: 'doc', content: [{ type: 'paragraph', content: [{ type: 'text', text: 'Hello, world!' }] }] }
 */
export function generateJSON(
  html: string,
  extensions: Extensions,
  options?: ParseOptions,
): Record<string, any> {
  if (typeof window === 'undefined') {
    throw new Error(
      'generateJSON can only be used in a browser environment\nIf you want to use this in a Node environment, use the `@tiptap/html/server` import instead.',
    )
  }

  const schema = getSchema(extensions)
  const doc: Document = new window.DOMParser().parseFromString(html, 'text/html')

  if (!doc) {
    throw new Error('Failed to parse HTML string')
  }

  return DOMParser.fromSchema(schema)
    .parse(doc.body as Node, options)
    .toJSON()
}

View on GitHub (pinned to 496d53afd7)

When it happens

Trigger: Thrown at packages/html/src/generateJSON.ts:33 when the library encounters an invalid state.

Common situations: See trigger scenarios.

Understand the failure class

Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

AI-assisted analysis of ueberdosis/tiptap@496d53afd7 (2026-08-26). Data as JSON: /api/errors/6a9f43f74bad37e6. Report an issue: GitHub.