Convert 001 to 003

Understanding 001 and 003 file formats

001 and 003 files are not traditional file formats but rather parts of a split archive. When large files are divided into smaller segments for easier storage or transfer, each segment is given a sequential extension such as .001, .002, .003, and so on. These files are typically created by file-splitting utilities or archiving tools like 7-Zip or WinRAR.

The .001 file is the first part of the split archive, while .003 is the third part. These files cannot be used independently; they must be rejoined to reconstruct the original file.

How to convert 001 to 003

Technically, you do not convert a .001 file to a .003 file. Instead, you combine all parts (including .001, .002, .003, etc.) to restore the original file. If you simply rename a .001 file to .003, the archive will become corrupt and unusable. The correct process is to use a file joining or extraction tool to merge all parts.

Best software for joining split files

• 7-Zip (Windows, free): Right-click the .001 file and select 7-Zip → Extract Here. Ensure all parts (.001, .002, .003, etc.) are in the same folder.
• WinRAR (Windows, paid/free trial): Right-click the .001 file and choose Extract Here or Extract to [folder].
• Keka (macOS, free): Open the .001 file with Keka to extract the complete archive.

Step-by-step process using 7-Zip

1. Place all split files (.001, .002, .003, etc.) in the same directory.
2. Right-click the .001 file.
3. Select 7-Zip → Extract Here.
4. 7-Zip will automatically combine all parts and extract the original file.

Important notes

• Do not attempt to convert or rename .001 to .003. This will not work and may corrupt your data.
• Always use a reliable extraction tool to join split files.
• Ensure all parts are present and named correctly before extraction.