Search Inside Custom Fields
Lets the site search also match text stored in custom fields, such as a subtitle, location or product code, not just titles and content.
Snippet Library
Search snippets for WordPress
Snippets that improve WordPress search: search custom fields and post types, exclude pages, redirect single results and highlight matching words. For content-heavy sites where visitors need to find things quickly.
Search WooCommerce Products by SKU
Lets shoppers find products by typing their SKU into the store search, including SKUs of individual variations.