How to Split Archives Using 7-Zip Command Line

Splitting large files or folders into smaller, manageable chunks makes them easier to transfer over networks, upload to services with file size limits, or store on external media. This guide covers how to use the 7-Zip command-line tool (7z) to create multi-volume archives using the volume switch (-v), explains how to specify chunk sizes, and details how to extract the split files back into their original format.

The Basic Syntax

To split an archive into multiple volumes, use the 7z executable with the a (add) command and the -v (volume size) switch:

7z a -v{Size}[Unit] {ArchiveName} {SourcePath}

Supported Size Units

The -v switch requires a numerical value followed by a unit specifier:

  • b – Bytes
  • k – Kilobytes
  • m – Megabytes
  • g – Gigabytes

Note: If no unit is specified, 7-Zip defaults to bytes.

Examples

1. Split a File into 100 Megabyte Chunks

To compress a large ISO file into multiple 100 MB .7z volumes:

7z a -v100m backup.7z disk_image.iso

This generates files named backup.7z.001, backup.7z.002, backup.7z.003, and so forth.

2. Split a Directory into 1 Gigabyte Chunks

To compress an entire directory into 1 GB volumes:

7z a -v1g project_archive.7z /path/to/project_folder/

3. Split into Volumes Without Compression

If you want to split files rapidly without spending CPU resources on compression, add the -mx0 (store only) switch:

7z a -mx0 -v500m fast_split.7z large_video.mp4

4. Create Split Standard ZIP Files

To create split archives using the .zip format instead of .7z, use the -tzip format switch:

7z a -tzip -v50m archive.zip documents/

For the ZIP format, 7-Zip creates files named archive.z01, archive.z02, and ends with archive.zip.

How to Extract Split Archives

To unpack a multi-volume archive, ensure all split parts are in the same folder. You only need to run the extraction command on the first volume:

For .7z multi-volume archives:

7z x backup.7z.001

For .zip multi-volume archives:

7z x archive.zip

7-Zip automatically detects and sequences the remaining parts to restore the original files.