EXTR Converter

Extract text from COW App Extractor files (EXTR)


Drop or upload your .EXTR file
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How to extract text from your EXTR file

  1. Click the "Select File" button above, and choose your EXTR file.
  2. You’ll see a preview, if available.
  3. Click the "Convert file to..." button to extract text information.

Convert EXTR to another file type

To convert EXTR extractor files to another format, you need COW App Extractor or other Encoded software.

Convert a file to EXTR

To convert other file formats to the "COW App Extractor File" file type, you need software like COW App Extractor or a similar tool.


About EXTR files

A .extr file is an encrypted application folder originally created for COW, an operating system for select mobile devices based on Linux that was discontinued before being released to the public. Originally, these files were distributed through the COW App Store. When downloaded, the COW system would automatically decrypt the .extr file, read the internal Main.py script, and install the embedded program. Unfortunately, because the OS was canceled, the .extr format is effectively dead and highly proprietary. The extreme disadvantage of this format is its aggressive encryption. You cannot open it with standard archive managers like WinRAR or 7-Zip, nor can you run it on an Android or iOS device. Furthermore, since the original decryption keys and installer are lost, extracting the pure source code or assets is virtually impossible for an average user. Standard converters fail completely when dealing with .extr files because they lack the proprietary decryption algorithm. It cannot be directly converted to standard app formats like APK or modern archives like ZIP. However, developers or archivists who need to inspect the file can try extracting raw data. Converting the file to hexadecimal (HEX) or pure text dumps (TXT) may reveal unencrypted metadata or fragments of the Main.py script. This is why this file format is difficult to open or convert: often only the original software can properly read or export the data. If our analysis detects a supported underlying or embedded format, viewing or conversion may still be possible.

Convert.Guru analyzes your EXTR file, detects the exact format, and lets you read the text inside.


FAQ

If you want to convert EXTR file to BASE64, HEX, BIN, ENC, CRYPT, AES, DES, RSA, PGP, GPG, ASC or KEY, you can use COW App Extractor or similar software from the "Encrypted App Package" category. In the File menu, look for Save As… or Export….

To convert CER, BIN, PEM, DER, KEY, P7S, PFX, ENC, P12, BASE64, P7B or HEX files to EXTR, try COW App Extractor or another comparable tool in the "Encrypted App Package" category.



The EXTR Converter Story

The history of Convert.Guru began over 25 years ago in California with Tom Simondi’s file-format database. A former contributor to Space Shuttle development and a software pioneer of the 1980s, Simondi established a trusted resource for file type analysis that was even referenced by Microsoft Windows XP. Today, we use modern technology to process and convert thousands of file formats while continually improving our EXTR converter.