.NET Search API - Documents advance searching and indexing

Basic and advance search functionality to retrieve full text and metadata from Microsoft Word, Excel, PowerPoint, PDF and Text documents.

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.NET document search API

GroupDocs.Search for .NET


GroupDocs.Search for .NET is a fascinating document search API. It extracts text and metadata from documents and performs advance searching and indexing operations on the basis of fuzzy and synonym algorithms. API also supports full text search. Information retrieval on the basis of full text search is based on indexes. All documents having at least one match in phrases, para or words will be listed as a result.

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Advanced Document Search API Features



Multiple basic and advance searching methods


Search Object Types


Search by Index


Simultaneous search on multiple indices


Index Email messages


Implement Dictionaries


Fuzzy and Synonym Search


Date and numeric range search


Password protected documents search


Search for Text occurrences, file names and types


Basic metadata fields


Simple and boolean queries


Faceted and Regular expression Regex queries


Document created and modified dates

Search by Index : How it works

API uses index frequently for performing search on that. Here is the way

  • Create Index : Index folder is created and documents are added/indexed to that folder. indices are created to collect, parse or store data for fast and accurate searching
  • Load Index : Index can be loaded if it was already created
  • Add Documents to Index : Once an index is created documents are added to it asynchronously.
  • Update Index : Index folder is always updated when ever a document is modified, added or deleted to keep search results up to date

Perform Search with default parameters - C#

 // Create index
Index  index = new Index(indexPath);
 // Add documents to index
 // Search in index
SearchResults searchResults =  index.Search("searchTerm");

Moreover following indexing functionalities also supported

  • Index separate files
  • Track all changes to file in index folder
  • View progress percentage of indexing or updating
  • Merging indexes
  • Prevent unnecessary file indexing
  • Subscribe to events
  • Indexing of metadata for PowerPoint files
  • Index Email Messages : Index Outlook PST and OST files email messages

Supported Dictionaries

Searching API supports following dictionaries

  • Alias Dictionary : Use abbreviations for frequent long queries
  • Homophone Dictionary : Manage list of heterographic homophones for improving search results
  • Letters Dictionary : Manage list of searchable letters
  • Stop Words Dictionary : Words which are filtered and not indexed like a, an, the, for etc

Document Search API Common Functionalities

Beside above features API also supports the following features related to search functionality

  • Total hit counts for a query
  • Limiting number of results
  • Correcting misspelled words in query before searching
  • Getting matched words in the found documents
  • Warning user in case of not supported settings
  • Recognizing queries written in different keyboard layout
  • Supporting different features in a single query
  • Defining table discrete function as a step function

Support and Learning Resources