Why Do A/B Testing Parameters Appear in My URLs, and How Can I Hide Them?

When a page is affected by a running test, Nelio A/B Testing may add a query parameter called nab to the URL. This parameter contains information Nelio uses to load the appropriate alternative content for the current visitor.

For example, you may see a URL such as:

https://example.com/blog/foo/?nab=...

To check which tests and variants are active on a page, use Nelio A/B Testing’s Debug Tools.

Why Do These Parameters Appear?

By default, Nelio A/B Testing uses query arguments to help WordPress load the appropriate alternative content for each visitor.

When a visitor accesses your site, Nelio A/B Testing determines whether they participate in any running tests and which variants they should see. When necessary, the plugin may redirect the visitor to a URL containing the corresponding nab parameter.

Where the Parameters Appear

The nab parameter may appear on pages affected by the scope of your running tests.

For example:

• A Menu Test may have a site-wide scope, so the parameter may appear across your site.
• A Page Test may only affect the tested page.
• A Theme Test may have a broader scope because the tested theme can affect multiple pages.

You can also configure Nelio A/B Testing to add the nab query argument to internal URLs to speed up navigation while tests are running.

How to Hide the Parameters From Your URLs

You can configure Nelio A/B Testing to remove the nab parameter from the browser’s URL after the appropriate alternative content has been loaded.

To enable this:

1. Go to Nelio A/B Testing → Settings.
2. Find the option Hide testing query arg nab from URL after alternative content has been properly loaded.
3. Enable it and save your changes.

Once enabled, Nelio A/B Testing removes the testing parameter from the browser’s URL after loading the appropriate alternative content.

Note About Google Analytics

Even if parameters disappear from the visitor-facing URL, your analytics tool may still log them. If needed, you can configure Google Analytics to ignore the nab parameter so it does not affect your reports.