Embed our 6×6 Sudoku on your site

A free, copy-paste 6×6 puzzle for blog posts, classroom pages, and puzzle hubs. The widget loads in well under a second, drops no cookies on your visitors, and works on every browser since 2018.

Live preview

This is the exact widget your readers will see. Tap a square, then tap a number.

Quick start

Two lines of HTML. The widget auto-discovers the placeholder div on page load.

<div data-sudoku-mountain
     data-difficulty="easy"
     data-lang="en"
     data-theme="auto"></div>
<script async src="https://sudokumountain.com/embed/sudoku/v1.js"></script>

Options

Configure via attributes on the placeholder div. Defaults shown.

data-theme: Theme. light, dark, or auto (matches the visitor's system theme).
data-difficulty: Difficulty. easy or medium. Easy puzzles take a couple of minutes; medium takes five to ten.
data-lang: Language. en or de. Affects the widget's labels (Mistakes, Time, Solved, etc.).
data-seed: Seed. Optional integer. Pass the same seed to always show the same puzzle — useful for daily-puzzle posts where the puzzle should be stable per page.

Iframe alternative

If your CMS won't let you run third-party JavaScript (Squarespace, some Wix configurations, hardened intranets), use an iframe instead. The iframe shape doesn't pass dofollow link equity but is otherwise functionally identical.

<iframe
  src="https://sudokumountain.com/embed/sudoku/v1?difficulty=easy&lang=en"
  width="380" height="540"
  frameborder="0"
  loading="lazy"
  title="Sudoku Mountain — 6×6"></iframe>

Privacy and cookies

The widget sets zero cookies on your page and does no fingerprinting. We log anonymous event counts (puzzle viewed, puzzle solved, link clicked) keyed by the Referer header your browser sends — that lets us tell how many sites use the widget without identifying any visitors. You don't need a consent banner to add this widget to your page.

Licensing

Free for any non-commercial or commercial site. The only ask: leave the small Sudoku Mountain footer link visible. Strip it and we'll feel sad, but technically there's no DRM stopping you. Don't strip it.

Versioning

v1.js is the stable bundle. We commit to never breaking the v1.js URL — patches ship in place, breaking changes will publish under v2.js with v1.js kept indefinitely. Your existing embeds will keep working.

Why we built this

Most embeddable puzzle widgets are slow, ad-laden, or both. We wanted a tiny bundle (under 50 KB), no third-party scripts, and zero impact on your page's Core Web Vitals. So we built one. If you run a blog about logic puzzles, an after-school programme, or a memory-care site, we'd love to be on your page.