Read this blog on Google site search alternatives free for more information.
With the recent death of Google Site Search, users have been testing other search solutions to try to determine which will be the preferred solution moving forward. For many customers, the price is a major factor so this list of Alternatives to Google Site Search is ranked based on value/ease for the dollar.
Elasticsearch (open source)
Hosted search as a service pricing begins at 79 USD per month. Requires developer bandwidth, as this only handles the search part. It does not provide you with a ready crawler and the capability to index pdf and other file types.
A very powerful search tool trusted by some large brands. Offering full-text search, support for high volume, data import via XML, JSON, and HTTP, comprehensive administration interfaces, scalability, geospatial searching, and near real-time indexing. Solr is a great solution but it requires you to have access to a Solr server. You can set one up or add Solr to an existing server, or there are a number of hosted options.
Sphinx is an open-source full-text search server. It is built in C++, hence offers great speed. Does not come with a crawler, hence has to set up a crawler, meaning more developer bandwidth.
This is a paid hosted SaaS solution, just like Google site search. Prices start at 9$ per month. Prices begin at 9 USD per month No ads. No developer bandwidth required, All you have to do is add a piece of code to your website and that’s it you have replaced your Google site search.