markitdown-ts

markitdown-ts converts various file types to Markdown without filesystem, process, stream, or any other runtime-specific dependencies. It can run in browsers, workers, edge functions, and all other modern JavaScript environments.

Supported formats

• Plain text, Markdown, CSV, and JSON
• HTML
• XML, RSS, and Atom feeds
• Jupyter notebooks (.ipynb)
• Word documents (.docx)
• Excel workbooks (.xlsx)
• PowerPoint presentations (.pptx)
• PDF documents (.pdf)
• ZIP archives (.zip), with nested files converted recursively
• Wikipedia, YouTube metadata, and Bing result pages supplied as HTML

Audio, image metadata, local-path, and YouTube transcript features from the original project are intentionally left out because their implementations depended on runtime-specific modules, binaries, streams, or filesystem access. They may be added back over time as alternative implementations are found. Want to see one added? Contributions are welcome!

Installation

pnpm install @ryangarber/markitdown-ts

Usage

import { MarkItDown } from "@ryangarber/markitdown-ts";

const bytes: Uint8Array = /* plain bytes */;

const result = await new MarkItDown().convert(bytes, {
  file_extension: ".txt"
});

console.log(result?.markdown);

The same convert method accepts:

• Uint8Array
• ArrayBuffer and SharedArrayBuffer
• DataView or any other typed array
• Blob and File
• Response

A file_extension is required when the source does not carry a recognized MIME type or filename.

const file = new File([docxBytes], "document.docx");
const result = await new MarkItDown().convert(file);

URLs

HTTP and HTTPS URLs are fetched with the global fetch. Pass a custom implementation when needed.

const result = await new MarkItDown().convert("https://example.com/article.html");

Browser requests remain subject to the remote server's CORS policy.

Responses

const response = await fetch("https://example.com/feed.xml");
const result = await new MarkItDown().convert(response);

API

type ByteSource = Uint8Array | ArrayBufferLike | ArrayBufferView | Blob;
type ConversionSource = ByteSource | Response | URL | string;

class MarkItDown {
  convert(source: ConversionSource, options?: ConverterOptions): Promise<ConverterResult>;

  /** @deprecated Pass the source directly to convert(). */
  convertBuffer(
    source: ByteSource,
    options: ConverterOptions & { file_extension: string }
  ): Promise<ConverterResult>;
}

convertBuffer remains as a compatibility alias, but convert(bytes, options) is preferred.

Development

pnpm install
pnpm check
pnpm test --run
pnpm build

Biome handles both formatting and linting. tsup produces ESM, CommonJS, source maps, and declarations in dist.

License

MIT License © 2026 Ryan Garber
MIT License © 2024 Vaibhav Raj