A1 Website Search Engine
Create search engines for online and offline website content.
15 Alternatives To A1 Website Search Engine

Algolia
Algolia’s Search API makes it easy to deliver a great search experience in your apps & websites. Algolia Search provides hosted full-text, numerical, faceted and geolocalized search.
Amazon CloudSearch
Amazon CloudSearch is a fully-managed service in the cloud that makes it easy to set up, manage, and scale a search solution for your website.
Apache Solr
Solr is an open source enterprise search server based on Lucene search library, with XML/HTTP and…

Apisearch
Apisearch official website.

CloudSh
Powerful search for your website with a few lines of JavaScript.
Cludo Site Search
The simple way to create a great search experience for your users and your team.
Findberry
Findberry is an internal site search service.

Search engine composer
Website search engine software: Create Search Engine for your online website, Intranet, CD and DVD in Minutes!

Site Search 360
Site Search 360 enhances and improves your built-in CMS search with autocompletion, semantic search, filters, facets, detailed analytics, and a whole lot of customization options.
Swiftype
The simplest way to add search to your website or application. Sign up for free.
Whoosh
Whoosh is a library of classes and functions for indexing text and then searching the index.