DEX File

What are DEX files and how to open them

Are you having problems opening a DEX file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your DEX files.

What is a DEX file?

DEX files have multiple uses, and Microsoft Excel Spreadsheet is one of them. Read more about the other uses further down the page.

Microsoft Excel Spreadsheet

The .dex file extension is used for a workbook or spreadsheet file format that Microsoft developed. These DEX files are normally found in Windows PCs where older versions of Microsoft Excel is installed. A .dex file can be created using these outdated Microsoft Excel versions.

A DEX file may contain formulas, equations, calculations, text, numbers, and formatting attributes usually found in other spreadsheet documents created using Microsoft Excel. This software is a popular spreadsheet application. Its more recent versions use the XLS file format for its default spreadsheet output files, while the newest Microsoft Excel versions, starting with MS Excel 2007, use the XLSX file format for its default spreadsheet output files. These .dex files can be opened and viewed using both old and new versions of Microsoft Excel. This software can also be used to edit a DEX file's content and export it to a more recent file format like XLS or XLSX.

How to open DEX files

We have identified two DEX openers that are compatible with this specific type of DEX file.

Programs that open Microsoft Excel Spreadsheet files

Last updated: October 22, 2026

All known file formats using extension .DEX

While Microsoft Excel Spreadsheet is a popular type of DEX-file, we know of 2 different uses of the .DEX file extension. Different software may use files with the same extension for different types of data.

Dalvik Dex Class

Dalvik Dex Class is a binary format used by the Dalvik virtual machine in the Android platform to package compiled Java bytecode and related metadata into a single executable file. It stores class definitions, method code, string constants and type information in a compact form that Android uses for running apps. The format is produced by Android's toolchain when Java or Kotlin source code is compiled and packaged into an APK.

The layout begins with a fixed-size header containing information such as version, checksum, file size, and signature. Following the header, the file includes various tables for strings (UTF-8 based), type identifiers, method and field identifiers, class definitions, and code items. Methods and classes are referenced by indices into these tables. The data are generally little-endian, with certain variable-length encodings (such as LEB128) used for efficiency. Dalvik Dex Class files are validated against constraints including matching checksum and signature, and correct ordering and offset values in the tables.

Internal recognition of the format is done through a magic signature at the very start of the file: the first eight bytes must match DEX_FILE_MAGIC (for example "dex\n035\0" or later versions like "dex\n039\0" depending on version), which helps tools confirm the file version.

While we have not verified the apps ourselves yet, our users have suggested seven different DEX openers which you will find listed below.

Various apps that use files with this extension

These apps are known to open certain types of DEX files. Remember, different programs may use DEX files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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