What is the MDX file format?
An .mdx file (also known as Media Data eXtended) is a disc image format generated by DAEMON Tools, a virtual drive software developed by DT Soft. It stores the complete contents of an optical disc - raw sector data and layout information - in a single binary container, and can be mounted as a virtual drive to emulate a physical CD, DVD or Blu-ray.
How .mdx improves on .mdf and .mds
The .mdx format was developed as a new, better version of the .mdf and .mds formats. The key difference is that a single .mdx file carries a complete disc image, while the older approach required splitting the data across two separate files. The .mdf and .mds files always had to occur together; without either one, it was impossible to read the image. By merging both into one file, .mdx simplified the storage and transfer of large disc images.
.mdx files can be freely converted into .iso format, and the reversed process is also possible. Applications such as UltraISO and PowerISO support this conversion on Windows. The format can also interoperate with .bin raw disc images via conversion tools.
Security & safety
RISK: MEDIUMThe format itself is data, but the disc image was a frequent vehicle for pirated games/software, which often bundle malware or "keygens" - scan anything downloaded as an .mdx and prefer the original source. Mounting the image is safe; running the installers/executables inside it is the real risk.
Format details
in a nutshell- Markdown + JSX source (.mdx) - A web-development text format (Next.js, Docusaurus, Astro) that embeds React/JSX components in Markdown; plain UTF-8 text edited in a code editor.
- MDX (Multidimensional Expressions) query (.mdx) - A saved text query in Microsoft's OLAP query language for SQL Server Analysis Services cubes.
- FoxPro/dBASE compound index (.mdx) - A binary multiple-index file for an old dBASE/FoxPro database table.
Programs that open MDX files
Windows4 apps
DAEMON Tools Lite
Freemium Mount the .mdx as a virtual drive - Windows treats it like an inserted CD/DVD. This is the program that created the format. Technical details
deep spec| Container type | Single-file binary disc image |
| Encoding | Binary (raw optical sector data) |
| Magic bytes | No fixed publicly documented signature; identified by DAEMON Tools software context |
| MIME type | application/octet-stream |
| Predecessor format | Replaces the two-file .mdf + .mds format pair |
| Disc types | CD, DVD, and Blu-ray disc images |
| Compression | Optional compressed mode supported by DAEMON Tools |
| Copy protection | Capable of storing copy-protected disc images (core DAEMON Tools feature) |
| Conversion targets | Convertible to and from .iso, .mdf/.mds, and .bin/.cue formats |
| Developer | DT Soft |
| Platform support | Primarily Windows; limited support elsewhere via compatibility layers |
| Virtual mounting | Mountable as a virtual CD/DVD/Blu-ray drive via DAEMON Tools |
| File count | Entire disc image in one file, versus two files required by the older .mdf/.mds format |
| Typical file size | Several hundred MB to several GB depending on the source disc |
| Released | DAEMON Tools .mdx, around 2009 (to replace the .mdf + .mds pair) |
| Specification | www.daemon-tools.cc |
MDX conversions
Community Q&A
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