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Verifying Installation

After installing the snippet, you need to confirm it is actually running on your website. There are three ways to do this: the A vs B Chrome extension, the automatic check in Project Settings, and a manual check using your browser's developer tools.

Chrome extension (easiest)

The A vs B Chrome extension can instantly detect whether the snippet is running on the current page. Install it from the Chrome Web Store and open your website. The extension icon will show a green indicator if the snippet is detected, or a grey indicator if it is not.

Beyond detection, the extension is also used for local development with the CLI tool — it connects to the avsb dev server and lets you preview variation changes in real time. See the Local Development docs for details.

Extension under review
The Chrome extension is currently under review by Google and may not yet appear in public search results. Use the direct link above to access it, or download it directly and load it manually as an unpacked extension.

Automatic check in Project Settings

A vs B automatically checks whether the snippet is live on your website and reports the result in Project Settings → Snippet.

  • Green “Snippet detected” badge — the snippet is live and A vs B was able to confirm it by visiting your website URL.
  • Yellow “Checking...” badge — the check is in progress. Wait a minute and refresh.
  • Red “Not detected” badge — A vs B could not find the snippet on your website. This could mean the snippet is not installed, the wrong URL is configured, or the site is not publicly accessible.
Info
The automatic check visits the URL you entered when creating your project. If your website requires authentication, is behind a firewall, or is a staging environment not accessible from the internet, the check will fail even if the snippet is installed correctly. In that case, use the manual check below.

Manual check using browser DevTools

Open your website in a browser and use the built-in developer tools to confirm the snippet loaded.

1

Open DevTools

In Chrome or Edge: press F12 or right-click anywhere on the page and choose Inspect. In Firefox: press F12. In Safari: enable the Develop menu in preferences, then choose Develop → Show Web Inspector.
2

Check the Network tab

Click the Network tab in DevTools. Reload the page with DevTools open. In the filter box, type snippet.js. You should see a request to cdn.avsb.cloud/snippet.js with a status of 200. If you see nothing, the snippet tag is not in your HTML.
3

Check the Elements tab

Click the Elements tab (called Inspector in Firefox). Press Ctrl+F (or Cmd+F on Mac) to search within the HTML. Search for avb. You should find a <script id="avb" ...> element in the <head>. If it is missing, the snippet tag was not added to your HTML template.
4

Check the Console tab

Click the Console tab. Type window.avsband press Enter. If the snippet has loaded successfully, you will see an object with A vs B's public API methods. If you see undefined, the snippet has not loaded yet (or at all).

Common issues

Ad blockers

Some ad blockers and privacy extensions block the A vs B snippet. This is expected behaviour for users who have ad blockers installed — their experience is the same as the control (no variation applied). If the snippet only fails to load in your own browser, disable your ad blocker and try again.

Content Security Policy (CSP) errors

If your website has a strict Content Security Policy, it may block the snippet from loading. In the Console tab of DevTools, look for errors that mention “Content Security Policy” or “Refused to load the script”. To fix this, add the A vs B domain to your CSP's script-src directive:

script-src 'self' https://cdn.avsb.cloud;

You will also need to allow the A vs B data ingestion endpoint inconnect-src:

connect-src 'self' https://cdn.avsb.cloud https://ingest.avsb.cloud;

Snippet placed in the body instead of head

The snippet will still work if placed in the <body>, but it will load later, which increases the likelihood of flicker. Move it to the <head> for best results.

Wrong snippet key

Double-check that the snippet key in your script tag URL matches the one shown in Project Settings → Snippet. If you have multiple projects, make sure you copied the key from the correct project.

Tip
If you are still stuck after checking all of the above, contact A vs B support at support@avsb.cloud with a link to the page where the snippet should be installed and a screenshot of your Network tab.