Paste to Markdown

Paste to Markdown is a browser-based HTML-to-Markdown converter built by Sinan Bolel (sbolel). It converts rich clipboard HTML into clean Markdown locally in the browser and is organized as a pnpm workspace with a reusable core package.

Live demo: sbolel.github.io/paste-to-markdown About the project: sbolel.github.io/paste-to-markdown/about

Ready to convert	Markdown output

What It Does

• Pastes rich HTML from documents, email, webpages, and editors through keyboard paste or the clipboard button.
• Keeps existing work intact when image-only input cannot be converted, with explanatory feedback.
• Converts content to Markdown locally in the browser.
• Lets you edit the raw Markdown and inspect a sanitized rendered preview.
• Lets you copy Markdown to the clipboard or download it as a Markdown file.
• Lets you clear and restore the current document during the browser session.
• Offers GitHub Flavored Markdown, CommonMark, Strict Markdown, and Custom Style presets, including supported GitHub-style tables.

Privacy

Paste to Markdown runs conversion in your browser. Pasted content is not sent to an app server. The current document is held only for the browser session so it can be restored after clearing; only formatting preferences are stored in the browser.

Workspace Structure

paste-to-markdown/
├── apps/
│   └── web/              # Maintained application (React + Vite + TypeScript)
└── packages/
    └── core/             # Shared conversion logic (@paste-to-markdown/core)

Getting Started

The checked-in .nvmrc selects Node 24; workspace tooling requires Node 24.15 or newer. With nvm, run nvm use, then install and start the workspace:

nvm use
pnpm install
pnpm dev

Open http://localhost:5173/paste-to-markdown/ in your browser.

Before running production browser checks for the first time, install their browsers:

pnpm --filter @paste-to-markdown/web exec playwright install chromium webkit

On Linux, add --with-deps to install the browsers' system dependencies, as CI does.

Scripts

Command	Description
pnpm dev	Start the website application
pnpm build	Build the core package and web app, then validate the Pages artifact
pnpm test	Run core and web unit tests
pnpm test:e2e	Test the built web artifact in Chromium and WebKit; run pnpm build first
pnpm lint	Lint TypeScript files
pnpm typecheck	Type-check all packages
pnpm format	Format source and documentation files
pnpm check	Run lint, type checks, unit tests, build, and production browser tests
pnpm audit:prod	Audit production dependencies

Packages

@paste-to-markdown/core

The shared runtime-agnostic conversion package provides convertHtmlToMarkdown(html, options?) and convertClipboardData(clipboardData, options?).

See the core package's runtime compatibility policy for the distinction between standalone consumers and workspace tooling.

apps/web

The React, Tailwind, Vite, and TypeScript website is the sole maintained application and GitHub Pages build. It consumes @paste-to-markdown/core for conversion while handling browser UI interactions, paste events, editable Markdown, sanitized preview, downloads, session-only restore, and formatting preferences. Fonts are bundled locally, with their licenses in public/font-licenses/.

The production build prerenders the homepage's public content with React. The heading, description, ready state, attribution, and navigation remain visible with JavaScript disabled; conversion requires JavaScript. The browser hydrates the same component tree, restores formatting preferences, and attaches paste handling before enabling conversion. The About page remains static HTML.

The build-only renderer runs with an empty document and deterministic defaults. It never reads clipboard content or saved browser preferences. Its temporary bundle is removed after rendering and is excluded from the Pages artifact. Development continues to use Vite's client rendering; production behavior is covered by the built-artifact browser tests in Chromium and WebKit at desktop and mobile sizes.

This private package uses the workspace's Node.js >=24.15.0 requirement for development and build tooling. The deployed application runs in the browser.

The historical root implementation in src/ remains outside the build as a reference. Make application changes in apps/web; the root implementation is not maintained.

Architecture Notes

• packages/core is runtime-agnostic: no DOM or browser UI concerns.
• apps/web handles all UI interactions.
• HTML-to-Markdown conversion uses Turndown with four shared Markdown presets. GitHub mode supports strikethrough, task-list markers, and simple GFM tables. See conversion behavior and fallbacks for complex tables, code, whitespace, and nonportable references.

Release

• Pull request titles must follow Conventional Commits so squash merges produce release-ready commits.
• fix: creates a patch release; feat: creates a minor release; feat!: or BREAKING CHANGE: creates a major release.
• Releases and GitHub tags are created automatically after merges to main; npm publishing is disabled.
• pnpm release:check loads the configured plugins and previews commit analysis and release-note rendering without credentials. It does not publish or verify release permissions.
• The CI/CD workflow validates the pnpm workspace and production dependency audit before release and Pages deployment. Its manual trigger follows the same gates.

Project Docs

• License: MIT License
• Contributing
• Code of Conduct
• Security