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.MDX·File Extension

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

Data & Texttext/mdxCompressible

Quick facts

Extension.mdx

File typeMDX Data & Text

MIME typetext/mdx

CategoryData & Text

Charset—

CompressibleYes

What is .mdx

What is a .mdx file?

A .mdx file is a MDX 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 text/mdx, and it is marked as compressible. When serving .mdx over HTTP, set the Content-Type header as shown in Developer info below.

Related entities: it maps to text/mdx and is used by MDX among others — and is delivered over HTTP via the Content-Type header.

How to open .mdx files

Use VS Code or Notepad++ to open and edit .mdx 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: text/mdx

Common software that reads/writes .mdx:

VS CodeNotepad++Sublime Textjq

Relation chain

.mdxextension of

format

MDX Data & Textserved as

mime type

text/mdxsent via header

http header

Related extensions

Related MIME types

Related programming languages

MDX

.mdx

Common uses

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

How to edit .mdx 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 .mdx files

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

Frequently asked questions

What programs can open .mdx 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 .mdx file?

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

What is the relationship between .mdx and the text/mdx MIME type?

text/mdx is the media type identifier used for .mdx files during network transfer (for example in the HTTP Content-Type header).

Sources & standards

Updated 2026-09-13

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

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