SeekStorm is a Search as a Service: web-scale, real-time, full text, instant search for your data and documents. SeekStorm is a Crawler as a Service: high-performance, focused crawler turns any website into JSON docs with structured data.
20x speed and 200x payload compared to Lucene 30x more queries & docs per $ spent than other SaaS
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.
Google Custom Search - Google Custom Search enables you to create a search engine for your website, your blog, or a collection of websites.
Google Cloud Search - Search across all your company's content in G Suite.
Sooqr - Sooqr Search provides relevant and innovative site search engine for the website.
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.
Klevu - Klevu offers instant site search solution for eCommerce stores.