Add Command (a)

The a (add) command creates new archives or adds files to existing archives.

Syntax

7z a [<switches>...] <archive_name> [<file_names>...] [@listfile]

Description

The add command is the primary method for creating archives. It can:

Create new archives
Add files to existing archives
Update existing files in archives with newer versions
Create multi-volume archives
Create self-extracting archives
Apply compression and encryption

Common Options

string

required

Name of the archive to create or update. The archive type is determined by the file extension (e.g., .7z, .zip, .tar.gz) or by the -t switch.

string

Files or directories to add. Supports wildcards (* and ?). If omitted, adds files from current directory.

string

Set archive type: 7z, zip, gzip, bzip2, tar, wim, xz, etc.Example: -t7z or -tzip

number

default:"5"

Set compression level:

-mx0 = Store (no compression)
-mx1 = Fastest compression
-mx3 = Fast compression
-mx5 = Normal compression (default)
-mx7 = Maximum compression
-mx9 = Ultra compression

string

Set compression method and parameters:

-m0=LZMA2 - Use LZMA2 method
-md={Size} - Dictionary size (16m, 32m, 64m, etc.)
-mfb={N} - Number of fast bytes (5-273)
-mmt={N} - Number of CPU threads

Example: -m0=LZMA2 -md=32m -mfb=64 -mmt=2

number

Set number of CPU threads for compression. Use -mmt=on for all available threads.Example: -mmt=4 or -mmt=on

string

Set password for archive encryption. Omit the password to be prompted.Example: -pMySecretPass or -p (prompts for password)

flag

Enable archive header encryption (7z format only). This hides file names and structure.

string

Create multi-volume archives. Size can use suffixes: b (bytes), k (KB), m (MB), g (GB).Example: -v100m (100 MB volumes)

flag

Recurse subdirectories. Include all files in subdirectories.

string

Exclude files by pattern. Can be used multiple times.Example: -x!*.tmp -x!*.bak

string

Include files by pattern.Example: -i!*.txt -i!*.doc

flag

Delete files after compression (move to archive).

flag

Compress files that are currently open/locked by other applications.

flag

Set case-sensitive mode for file names.

string

Create self-extracting archive. Optionally specify SFX module.Example: -sfx7zCon.sfx

string

Set working (temporary) directory. Empty path means use system temp directory.

string

Read data from stdin. Optionally specify file name within archive.

flag

Set archive timestamp from the most recently modified file.

flag

Store hard links as links (not as separate files).

flag

Store symbolic links as links (not as file contents).

Examples

Create a basic 7z archive

7z a archive.7z files/

Output:

7-Zip 23.01 (x64) : Copyright (c) 1999-2023 Igor Pavlov : 2023-06-20

Scanning the drive:
3 folders, 12 files, 45678 bytes (45 KiB)

Creating archive: archive.7z

Add new data to archive: 3 folders, 12 files, 45678 bytes (45 KiB)

Files read from disk: 12
Archive size: 23456 bytes (23 KiB)
Everything is Ok

Create archive with maximum compression

7z a -t7z -mx=9 archive.7z files/

Create password-protected archive with header encryption

7z a -p -mhe=on secret.7z files/

Prompts for password:

Enter password (will not be echoed):
Verify password (will not be echoed):

Create ZIP archive with normal compression

7z a -tzip archive.zip files/

Create multi-volume archive (100 MB volumes)

7z a -v100m archive.7z large_files/

Creates:

archive.7z.001
archive.7z.002
archive.7z.003
...

Add files with specific extension

7z a archive.7z *.txt -r

Exclude specific files

7z a archive.7z files/ -x!*.tmp -x!*.bak

Create archive and delete source files

7z a -sdel archive.7z files/

Create archive with specific compression method

7z a -t7z -m0=LZMA2 -mx=9 -md=64m -mfb=64 -mmt=4 archive.7z files/

Create archive from stdin

cat file.txt | 7z a -si archive.7z

Create self-extracting archive

7z a -sfx archive.exe files/

Update existing archive

7z a existing.7z newfile.txt

Create tar.gz archive (two-step compression)

7z a -ttar archive.tar files/
7z a -tgzip archive.tar.gz archive.tar

Or in one command:

tar -cf - files/ | 7z a -si -tgzip archive.tar.gz

Advanced Usage

Solid Archives

For maximum compression on similar files:

7z a -t7z -m0=lzma2 -mx=9 -ms=on archive.7z files/

Multiple CPU Threads

Use all available CPU cores:

7z a -mmt=on archive.7z files/

Custom Dictionary Size

Larger dictionary = better compression but more memory:

7z a -md=256m archive.7z files/

When adding files to an existing archive, 7-Zip updates files that have been modified and adds new files. Use the -u (update) command for more control over update behavior.

The -sdel switch permanently deletes source files after compression. Use with caution!

For best compression of text files, use:

7z a -t7z -m0=PPMd -mx=9 archive.7z textfiles/

PPMd algorithm works better for text than LZMA2.

Update Command (u) - Update files with more options
Extract Command (x, e) - Extract files from archives
Delete Command (d) - Remove files from archives

Getting Started

Command Reference

Compression Methods

Archive Formats

Advanced Usage

Add Command (a)

Syntax

Description

Common Options

Examples

Create a basic 7z archive

Create archive with maximum compression

Create password-protected archive with header encryption

Create ZIP archive with normal compression

Create multi-volume archive (100 MB volumes)

Add files with specific extension

Exclude specific files

Create archive and delete source files

Create archive with specific compression method

Create archive from stdin

Create self-extracting archive

Update existing archive

Create tar.gz archive (two-step compression)

Advanced Usage

Solid Archives

Multiple CPU Threads

Custom Dictionary Size

​Syntax

​Description

​Common Options

​Examples

​Create a basic 7z archive

​Create archive with maximum compression

​Create password-protected archive with header encryption

​Create ZIP archive with normal compression

​Create multi-volume archive (100 MB volumes)

​Add files with specific extension

​Exclude specific files

​Create archive and delete source files

​Create archive with specific compression method

​Create archive from stdin

​Create self-extracting archive

​Update existing archive

​Create tar.gz archive (two-step compression)

​Advanced Usage

​Solid Archives

​Multiple CPU Threads

​Custom Dictionary Size

​Related Commands

Syntax

Description

Common Options

Examples

Create a basic 7z archive

Create archive with maximum compression

Create password-protected archive with header encryption

Create ZIP archive with normal compression

Create multi-volume archive (100 MB volumes)

Add files with specific extension

Exclude specific files

Create archive and delete source files

Create archive with specific compression method

Create archive from stdin

Create self-extracting archive

Update existing archive

Create tar.gz archive (two-step compression)

Advanced Usage

Solid Archives

Multiple CPU Threads

Custom Dictionary Size

Related Commands