How to Add the Double-Slit Experiment to Your Website

You can add a full double-slit experiment to any website, blog, or classroom page with a single line of code — free, with no sign-up, no plugin, and no script to install. Visitors send a wave through two slits and watch bright and dark fringes appear, then switch to Particles and fire photons one at a time — each lands as a single random dot, yet the same fringe pattern builds up from thousands of them. This guide covers the fastest way to embed the tool, what it teaches, and where it works.

The quickest way: paste one embed snippet

An embed is just an <iframe> that loads the simulator from lkforge.com, plus a small credit line. Copy this into your page’s HTML where you want the widget to appear:

<iframe src="https://lkforge.com/embed/double-slit-experiment/"
        width="100%" height="1020" loading="lazy"
        style="border:0;max-width:560px"
        title="Double-Slit Experiment by LK Forge"></iframe>
<p><a href="https://lkforge.com/tools/physics/double-slit-experiment/">Double-Slit Experiment</a>
   by <a href="https://lkforge.com/">LK Forge</a></p>

The <iframe> is the live simulator; the <p> underneath is a plain credit link. Keep that line — the visible link is what keeps the widget free to embed. You can also copy this exact code straight from the LK Forge widget gallery.

What the widget shows

The simulator opens already firing particles, so a visitor watches the fringes build up immediately and can then take control:

• Wave or particles: see the continuous interference pattern, or fire photons one at a time and watch the same fringes emerge dot by dot.
• One slit or two: close a slit to make the interference collapse into a single diffraction blob, then reopen it and watch the fringes return.
• Slit separation, slit width, wavelength, screen distance: sliders change the geometry live, spreading or tightening the fringes.
• Diffraction envelope: each slit's finite width shapes a sinc² envelope that dims the outer fringes, so widening a slit narrows the envelope.
• Live readout: the panel tracks the particle count, the fringe spacing Δy = λL/d and the wavelength.

Pick the right height

The snippet uses height="1020", which fits the experiment canvas, the view and slit toggles, the buttons, the sliders and the readout without clipping even on a narrow phone, where they stack into one column. On a wider page the widget centres within its max-width:560px. That single height works across screen sizes, so there is nothing to tweak for mobile.

Where it works

Because it is a standard iframe, the embed works anywhere you can add HTML:

• WordPress: add a Custom HTML block and paste the snippet.
• Squarespace: use a Code / Embed block.
• Wix: add an Embed HTML / iframe element.
• Ghost: insert an HTML card.
• Notion: paste the /embed/double-slit-experiment/ URL and choose "Create embed".
• Plain HTML, an intranet, or a lesson page: paste the snippet straight into the markup.

That’s the whole job. Copy the embed code from the widget gallery and paste it wherever a physics lesson or a blog post on interference, diffraction or wave–particle duality needs an experiment students can actually fire.