BigCommerce themes can have a built-in Quick Search. When Instant Search Widget is displayed too, it doesn't look nice. To avoid this, you should:

  1. Paste the Searchanise code into your site's <head> section to boost the widget's loading if you use the Stencil theme platform. Look here for the instructions.
  2. Turn off Quick Search in your theme. Here you can find guides for some BigCommerce themes on how to do that:
    1. Cornerstone Theme
    2. Supermarket Theme
Tip
If you didn’t find the guide for your theme, we recommend you look at the theme documentation or contact the theme support team.

Cornerstone Theme

Steps:

  1. Go to BigCommerce admin panel > Dashboard > Storefront > MyThemes.
  2. Click the Advanced drop-down menu of the current theme. A list of actions for the theme will appear.
  3. Select the Edit Theme Files option. You’ll be redirected to the Theme Editor. 
  4. Go to Templates > Components > Search > quick-results.html.
  5. Сomment out the entire code in the file.
  6. Save the changes.

Supermarket Theme

Look here for the theme instructions.