Beginner 5 min read

Installing on an HTML Site

Add Split Test Pro to any website with a single script tag. Sign up, copy the snippet, paste it into your <head>, and verify it's running — under five minutes.

Split Test Pro runs on any website that lets you add a <script> tag to the page. There’s nothing to compile, no SDK to install, and no framework requirements. This guide walks you through signing up, installing the snippet, and confirming it’s working.

Step 1: Create Your Account

Sign up and create your workspace

Go to splittestpro.com and create an account. You’ll be prompted to create a workspace — this is the container for your experiments, team members, and billing for a single site.

Give the workspace a name (usually your site or brand) and the domain you’ll be testing on.

One workspace per site. You can add more workspaces later if you manage multiple properties.

Step 2: Copy Your Install Snippet

Open Settings → Script & API

In the Split Test Pro app, click Settings in the sidebar, then scroll to the Script & API section. You’ll see a snippet like this:

<script
  src="https://app.splittestpro.com/experiment.js"
  data-api-key="YOUR_API_KEY"
  async
></script>

Click Copy snippet to grab it.

The snippet is unique to your workspace — the data-api-key is what links it back to your account.

Step 3: Paste It Into Your Site

Add the snippet inside <head>

Paste the snippet inside the <head> of your site, before any other Split Test Pro–related script and before the closing </head> tag. It needs to load early so it can inject variant CSS before the page paints.

Plain HTML / static sites: edit your template’s <head> block.
WordPress: use a header-injection plugin (e.g., “Insert Headers and Footers”) or your theme’s header customizer.
Webflow / Squarespace / Wix: look for “custom code” or “header code injection” in site settings.
Next.js / Nuxt / Astro: add it to your global layout’s <head> (e.g., app/layout.tsx, _app.js, or the equivalent).
Google Tag Manager: create a Custom HTML tag that fires on All Pages and As soon as possible.

Step 4: Verify It’s Running

Open your site and check the network tab

Visit any page where you installed the snippet. Open your browser’s DevTools (F12 or right-click → Inspect) and switch to the Network tab. Reload the page.

Filter for experiment.js. You should see a request to app.splittestpro.com returning 200 OK.

If you see experiment.js with a 200 status, you're live.

Confirm in the Split Test Pro app

Back in the Split Test Pro Settings → Script & API section, you’ll see a green “Connected” indicator once the script has phoned home from your domain. This can take up to a minute after the first pageview.

Single-Page Apps

If your site is a single-page application (React, Vue, etc.) that uses client-side routing, the script binds variants on initial page load and does not automatically rerun on pushState route changes. See Single-Page Apps for the workaround.

By default, the script respects Do Not Track and Global Privacy Control signals. If you use a cookie-consent banner, you can hold the script back until consent is given. See Privacy and Consent for the details.

Troubleshooting

Script returning 403 or 404. The data-api-key is wrong. Re-copy the snippet from Settings.
“Connected” indicator never turns green. Confirm the script loads on the public-facing domain you registered with the workspace, not just on a staging URL.
Tag manager strips async or moves the tag. That’s fine — the script handles being loaded out of order, but it should still be in <head> rather than at the end of <body>.

For more, see Troubleshooting.

Next Steps

Take the dashboard tour to learn the layout, then create Your First Experiment.

Ready to start testing?

Install Split Test Pro and run your first experiment today.

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