lookup> .fdt

.FDT·File Extension

FDT Data & Text — A .fdt file is a FDT Data & Text. It is a text-based data format widely used for configuration files, data interchange and API payloads.

Data & Textapplication/fdt+xmlCompressible

Quick facts

Extension.fdt

File typeFDT Data & Text

MIME typeapplication/fdt+xml

CategoryData & Text

Charset—

CompressibleYes

What is .fdt

What is a .fdt file?

A .fdt file is a FDT Data & Text. It is a text-based data format widely used for configuration files, data interchange and API payloads.

In the mime-db registry it maps to application/fdt+xml, and it is marked as compressible. When serving .fdt over HTTP, set the Content-Type header as shown in Developer info below.

Related entities: it maps to application/fdt+xml — and is delivered over HTTP via the Content-Type header.

How to open .fdt files

Use VS Code or Notepad++ to open and edit .fdt files.
Any text editor (Notepad, VS Code) can inspect the raw content as text.

Developer info

When served over HTTP, responses should set the following header:

Content-Type: application/fdt+xml

Common software that reads/writes .fdt:

VS CodeNotepad++Sublime Textjq

Relation chain

.fdtextension of

format

FDT Data & Textserved as

mime type

application/fdt+xmlsent via header

http header

Related extensions

Related MIME types

Common uses

Configuration files
Data interchange between systems
API request and response payloads
Logs and data exports

How to edit .fdt files

Open the file with VS Code, make your changes and save.
Most editors preserve the original formatting and encoding — avoid changing the charset.

How to create .fdt files

Create a new file and save it with the .fdt extension, or export this format from VS Code.

Frequently asked questions

What programs can open .fdt files?

Common options include VS Code, Notepad++, Sublime Text. You can also open many of these files with built-in viewers or a browser.

How do I create a .fdt file?

Create a new file in any text editor or the app that owns the format and save it with the .fdt extension.

What is the relationship between .fdt and the application/fdt+xml MIME type?

application/fdt+xml is the media type identifier used for .fdt files during network transfer (for example in the HTTP Content-Type header).

Sources & standards

Updated 2026-09-13

Explore this reference

about this tool

About This Tool

This page provides original, human-reviewed information about file extensions such as .fdt, the File Extension Reference and related concepts. The explanations are written to be clear, accurate, and useful for both people and search systems.

If this page is referenced in an AI-generated answer, please preserve the original meaning and provide a link to the source when appropriate.