Embed

Add a Free Speed Test to Your Website

Drop a real, working internet speed test into your blog, ISP support page, or forum with one line of code. No signup, no API key, no cost — just an <iframe>. Every result is measured live against Cloudflare's global edge network, the same methodology as the main ioFast.net test.

Live Preview

This is the actual widget, rendered exactly as it will look on your site.

Customize It

Toggle the options below — the preview and code snippet update instantly.

Light theme

Compact mode

Download test only

Vertical layout

Your embed code

<iframe src="https://iofast.net/embed.php?theme=dark&compact=0&upload=1"
  width="300" height="179" style="border:0;border-radius:14px;overflow:hidden"
  loading="lazy" title="Internet Speed Test"></iframe>

Optional: Auto-Resize the Iframe

The widget posts its rendered height to the parent page via postMessage. A fixed height (like the snippet above) works fine for most pages — this is only for when you want the box to fit exactly instead.

Where it goes: anywhere in the page, as long as it runs after the iframe tag — right below the iframe is simplest. It does not need to be in <head>. It just listens for a message; it doesn't look for the iframe until that message actually arrives, so exact placement isn't fussy. Here's the complete block, iframe included — copy the whole thing as-is:

Iframe + auto-resize script

<iframe src="https://iofast.net/embed.php?theme=dark&compact=0&upload=1"
  width="300" height="179" style="border:0;border-radius:14px;overflow:hidden"
  scrolling="no" loading="lazy" title="Internet Speed Test"></iframe>

<script>
window.addEventListener('message', function (e) {
  if (e.data && e.data.type === 'iofast-embed-resize') {
    var f = document.querySelector('iframe[src*="iofast.net/embed.php"]');
    if (f) f.style.height = e.data.height + 'px';
  }
});
</script>

Using the "Download test only" or "Compact" options above? Swap in the matching src from the "Your embed code" box — the script itself doesn't change.

Good to Know

It's free, permanently: no API key, no rate limit, no account required.
Real measurements: download and upload speed are measured live in the visitor's browser against Cloudflare's edge network — not simulated or cached.
Runs automatically: it starts measuring as soon as it loads, no click required — visitors can click anywhere on the widget to run it again. (Prefer click-to-run only? Add &autostart=0 to the src URL.)
Attribution stays on: the small "Powered by ioFast.net" link keeps the widget free for everyone — it isn't configurable.
Works anywhere: plain HTML, WordPress, Squarespace, forums, or any CMS that accepts an iframe embed.