What’s the best way to serve a React/Next.js site as Markdown or plain text?

HTML-to-Markdown conversion is fairly straightforward for ordinary content—headings, paragraphs, links, lists, emphasis, and code blocks all have common equivalents. However, HTML features such as JavaScript widgets, forms, layout elements, and custom components do not have direct Markdown representations. Decide what content should remain accessible in the text version and provide a meaningful fallback for unsupported elements.

The usual approach is to keep Markdown or structured content as the source of truth, then render it to HTML for browsers and expose the original or transformed content as Markdown/plain text for other clients. In a Next.js app, tools such as remark, unified, or Markdoc can parse and render Markdown. Converting already-generated HTML back into Markdown is possible, but it can be lossy and difficult to maintain, especially with interactive components.

A better architecture is to store content in a structured, presentation-independent model—Markdown, a CMS schema, or JSON—and let the backend negotiate the response format. Return HTML to browsers and Markdown or plain text to clients that request it through the Accept header. Avoid using generated HTML as your canonical data, because converting it back later can lose structure and meaning.

Markdown is mainly a lightweight formatting syntax, not a replacement for HTML. It works well for articles and documentation, but it cannot represent most interactive UI. Keep the full HTML/React experience for normal users and create a deliberate text endpoint that extracts the important headings, prose, links, lists, and code instead of trying to serialize every visual component.