File Extension DTD

  • Full name
    Document Type Definition Format
  • Developer
  • Popularity
Have you encountered a problem with a DTD file? Don’t you know which program opens a file with this extension? You will find all the information you need about working with a DTD file here. In the further part of this page we have added a list of programs that should open your DTD file. It is enough you choose a proper application for your operating system, download and install it.


DTD files are called document type definition files. In DTD files are text files that contain, among other things, element types, element attributes, and notations, and specify their order and nesting. A DTD file defines the structure of other XML, SGL, HTML or XHTML documents.

Usually DTD files in a web page are referenced via a URL, so often the xhtml1-transitional.Dtd or xhtml1-strict.Dtd is included via DOCTYPE statement. Furthermore, DTD files are also used to validate documents. For example, XML documents can be checked for correct structure and element properties to ensure that they can be read correctly.

DTD files can be opened and edited in any text editor, but can only be used with an XML editor or other programs that can parse XML, XHTML, HTML or SGL.

Programs which can open a DTD file

How to open a DTD file? Advice and guidance

Absolutely most often appearing reason that prevents you from opening the DTD file is the lack of a proper application to support it in your operating system. It is notably the first thing you need to address. When one of the programs to support a DTD file from the list is already installed, you can try to rerun the file. The system should display a message asking you to choose a primary application to support DTD files. At this point we are looking for disk space where the application was installed in and we can link it with a DTD file. Since then, our operating system will use the selected program to support all DTD files.

Other issues

Despite the described problem with DTD there may be many more problems. If the existing operations were not effective, get involved with the following matters:

- verify that the DTD file is not damaged and that it has been downloaded or copied in whole
- verify that the file has a file extension that has not been intentionally changed (for example, if it do not contain other information than its extension suggests)
- make sure again whether the DTD file type is linked in the operating system with a proper program
- make sure that the file is not infected with a virus and you have up to date software and drivers.

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