Overview of Word library (DocIO)

26 Apr 20241 minute to read

Essential DocIO is a native Java Word library that is used by developers to create, read, write, and convert the Microsoft Word documents in the Java application without Microsoft Word or interop dependencies.

It is a non-UI component that provides a full-fledged document instance model similar to the Microsoft Office COM libraries to iterate with the document elements explicitly and perform necessary manipulation. It is built from scratch in Java and does not require Microsoft Word to be installed in the machine. It supports Word 2007 and later versions documents.

Key Features

  • Support to create Word document from scratch.
  • Support to open, modify, and save the existing Word documents.
  • Advanced Mail merge support with different data sources.
  • Ability to create or edit Word 2007 and later version documents, and convert them to commonly used file formats such as WordML, TXT, HTML and vice versa.
  • Ability to create and manipulate shapes, and group shape in the DOCX and WordML format documents.
  • Ability to read and write the built-in and custom document properties.
  • Support to insert and edit the form fields.
  • Ability to insert the bookmarks and navigate corresponding bookmarks to insert, replace, and delete content.

Compatible Microsoft Word Versions

  • Microsoft Word 2007
  • Microsoft Word 2010
  • Microsoft Word 2013
  • Microsoft Word 2016
  • Microsoft Word 2019


Sometimes a Java application may throw an error like this “Java.Lang.OutOfMemoryError.” Usually, this error occurs due to insufficient RAM heap space to allocate an object in the Java heap. To avoid this kind of problem, we suggest increasing the JVM heap size.


Currently, Essential DocIO supports .DOCX, .DOTX, .DOTM, .DOCM, .WordML, .RTF, .Txt, WordML, HTML. Please refer to the supported and unsupported features in the essential DocIO.