Instant Search For Magento 2 extension provides users with quick drop-down suggestions on products, categories, content page or blog posts when they type in the keywords.

Ability to display search results of products, categories, CMS page or Blog (compatible with Blog for Magento 2 extension) 

Ability to adjust number of search results in drop-down list 

Admin is able to turn the function on/ off and re-arrange the position of each section in drop-down list

Lightning speed search by Ajax without re-loading page

Get details: https://www.magesolution.com/instant-search.html