How to Add a Wave on a String to Your Website

You can add a full wave-on-a-string simulator 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 pulse racing down a string and watch it bounce back, flip the far end between fixed and free to see the reflection turn upside down or stay upright, or drive the end steadily until the string locks into a shimmering standing wave. 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/wave-on-a-string/"
        width="100%" height="940" loading="lazy"
        style="border:0;max-width:560px"
        title="Wave on a String by LK Forge"></iframe>
<p><a href="https://lkforge.com/tools/physics/wave-on-a-string/">Wave on a String</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 driving the string, so a visitor sees the wave immediately and can then take control:

• Pulse or oscillate: fire a single travelling pulse, or drive the end continuously to build a wave train.
• Fixed or free end: toggle the far end and send a pulse to watch the reflection flip upside down at a fixed end and stay upright at a free one.
• Wave speed, frequency, amplitude, damping: sliders change the physics live, so you can tune the string toward a resonance.
• Standing waves and harmonics: at the right frequencies the string locks into fixed nodes and swinging antinodes, with dots marking each node.
• Live readout: the panel reports the wavelength in cells, the harmonic number and the driving frequency, all obeying v = f·λ.

Pick the right height

The snippet uses height="940", which fits the string canvas, the mode and end 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/wave-on-a-string/ 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 waves, reflection, resonance or standing waves needs a string students can actually pluck and drive.