Is embedding the simple pendulum free?

Yes. It is free to embed on any site, with no account, no API key and no usage limits. The whole simulation runs in your visitor’s own browser, so there is no server cost — we only ask that you keep the small "Simple Pendulum Simulator by LK Forge" credit line that comes with the embed code.

What can visitors do with the embedded pendulum?

They can press play to watch a single bob swing and trace its arc as a glowing trail, drag the bob to set a new starting angle, and use the sliders to change the length, gravity, damping and simulation speed. A live readout shows the elapsed time, the measured period, and the ideal small-angle period T = 2π√(L/g) for comparison.

Does the embed teach the period formula?

Yes — that is its main teaching point. It shows the measured period beside the ideal T = 2π√(L/g), so students can see that the mass of the bob never changes the period, while length and gravity do. Push the pendulum to a wide swing and the measured period visibly climbs above the ideal, which is where the small-angle approximation breaks down.

What iframe height should I use, especially on mobile?

The snippet ships with height="800", which is tall enough that the canvas, controls and readouts all fit without clipping even on a narrow phone where everything stacks into a single column. On a wider page the widget simply centres within its max-width of 560px. If you want it shorter you can lower the height, but 800 is the safe default across screen sizes.

Where can I embed it — WordPress, Wix, Squarespace, Notion?

Anywhere you can add HTML, because it is a standard iframe. In WordPress use a Custom HTML block; in Squarespace a Code/Embed block; in Wix an Embed HTML element; in Ghost an HTML card; in Notion paste the /embed/simple-pendulum/ URL as an embed. On a plain HTML page or an intranet, paste the snippet straight into the markup.

Does the embedded pendulum track visitors or set cookies?

No. Everything runs locally in the visitor’s browser — nothing is uploaded. The embed sets no tracking cookies and sends no analytics, so it is safe to place on a privacy-sensitive site, an intranet, or a page for students.

Widgets

How to Add a Simple Pendulum Simulator to Your Website

LK Forge · 4 min read · Updated September 2026

You can add a full simple pendulum 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 press play and watch a bob swing under gravity, tracing its arc as a glowing trail, and read the period off a live panel. This guide covers the fastest way to embed the Simple Pendulum Simulator, 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/simple-pendulum/"
        width="100%" height="800" loading="lazy"
        style="border:0;max-width:560px"
        title="Simple Pendulum Simulator by LK Forge"></iframe>
<p><a href="https://lkforge.com/tools/physics/simple-pendulum/">Simple Pendulum Simulator</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 swinging, so a visitor sees the motion immediately and can then take control:

Swing and trail: the bob traces its arc back and forth as a fading trail, making the shape of the motion easy to see.
Drag to set the angle: grab the bob and release it from any starting angle to compare a gentle swing with a wide one.
Length, gravity, damping, speed: sliders change the physics live — shorten the string or raise gravity and the swing quickens; add damping and it slowly settles.
Measured vs ideal period: the readout shows the measured period beside the ideal T = 2π√(L/g), so the small-angle approximation — and where it breaks down — is visible in numbers.

Pick the right height

The snippet uses height="800", which fits the canvas, the controls and the readouts 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/simple-pendulum/ 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 oscillation, gravity or timekeeping needs a pendulum students can actually swing.

Grab the embed code from the LK Forge widget gallery — free, no sign-up.

Open the Simple Pendulum Simulator

Frequently asked questions

Is embedding the simple pendulum free?: Yes. It is free to embed on any site, with no account, no API key and no usage limits. The whole simulation runs in your visitor’s own browser, so there is no server cost — we only ask that you keep the small "Simple Pendulum Simulator by LK Forge" credit line that comes with the embed code.
What can visitors do with the embedded pendulum?: They can press play to watch a single bob swing and trace its arc as a glowing trail, drag the bob to set a new starting angle, and use the sliders to change the length, gravity, damping and simulation speed. A live readout shows the elapsed time, the measured period, and the ideal small-angle period T = 2π√(L/g) for comparison.
Does the embed teach the period formula?: Yes — that is its main teaching point. It shows the measured period beside the ideal T = 2π√(L/g), so students can see that the mass of the bob never changes the period, while length and gravity do. Push the pendulum to a wide swing and the measured period visibly climbs above the ideal, which is where the small-angle approximation breaks down.
What iframe height should I use, especially on mobile?: The snippet ships with height="800", which is tall enough that the canvas, controls and readouts all fit without clipping even on a narrow phone where everything stacks into a single column. On a wider page the widget simply centres within its max-width of 560px. If you want it shorter you can lower the height, but 800 is the safe default across screen sizes.
Where can I embed it — WordPress, Wix, Squarespace, Notion?: Anywhere you can add HTML, because it is a standard iframe. In WordPress use a Custom HTML block; in Squarespace a Code/Embed block; in Wix an Embed HTML element; in Ghost an HTML card; in Notion paste the /embed/simple-pendulum/ URL as an embed. On a plain HTML page or an intranet, paste the snippet straight into the markup.
Does the embedded pendulum track visitors or set cookies?: No. Everything runs locally in the visitor’s browser — nothing is uploaded. The embed sets no tracking cookies and sends no analytics, so it is safe to place on a privacy-sensitive site, an intranet, or a page for students.