Very lightweight jQuery script that wraps search terms in an HTML5 mark tag when referer is a search engine or within wp search results.
Highlights search terms within WordPress generated search results or when referrer is a non-secure search engine, both on the search results page and on the post page itself.
This plugin is light weight and has no options. It started as very simple fusion between How to Highlight Search Terms with jQuery - theme hack by Thaya Kareeson and Search Hilite by Ryan Boren. It has since evolved with many optimizations, HTML5 and bbPress support.
Many WordPress sites are already top-heavy with all kinds of resource hungry plugins that require a lot of options to be set and subsequently more database queries. The Highlight Search Terms plugin for WordPress is constructed to be as low impact / low resource demanding as possible, keeping server response and page load times low. This is done by going without any back-end options page, no filtering of post content and no extra database entries. A limited amount of hooks are used. The rest is done by jQuery javascript extention and your own CSS.
Features
Read more on https://wordpress.org/plugins/highlight-search-terms/