License Information

Overview

License Summary by Component

The 7-Zip source code uses different licenses depending on the specific files:

Component	License	Notes
Most source files	GNU LGPL v2.1+	Default license for files without explicit license statements
RAR decompression	GNU LGPL + unRAR restriction	`CPP/7zip/Compress/Rar*` files
LZFSE decoder	BSD 3-clause	`CPP/7zip/Compress/LzfseDecoder.cpp`
ZSTD decoder	BSD 3-clause	`C/ZstdDec.c`
XXH64 hash	BSD 2-clause	`C/Xxh64.c`
Public domain files	Public domain	When explicitly stated in source file
LZMA SDK	Public domain	Written by Igor Pavlov

If a source file contains no license information, it falls under the GNU LGPL license.

GNU LGPL License

GNU Lesser General Public License v2.1

Most of the 7-Zip source code is licensed under the GNU Lesser General Public License (LGPL) version 2.1 or later.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, you can get a copy of 
the GNU Lesser General Public License from http://www.gnu.org/

Key Points:

Free to use, modify, and redistribute
No warranty provided
Must comply with LGPL terms for distribution
See DOC/copying.txt for full license text

unRAR License Restriction

The RAR decompression code has additional restrictions beyond the GNU LGPL. You must comply with BOTH the GNU LGPL and the unRAR license restriction.

Files Affected

All files matching the pattern CPP/7zip/Compress/Rar* are subject to the “GNU LGPL with unRAR license restriction.”

unRAR License Terms

unRAR Restriction Details

The decompression engine for RAR archives was developed using source code from the unRAR program.Copyright: All copyrights to original unRAR code are owned by Alexander Roshal.Key Restrictions:

Cannot recreate RAR compression algorithm - The unRAR sources cannot be used to re-create the RAR compression algorithm, which is proprietary.
Distribution requirements - Distribution of modified unRAR sources (in separate form or as part of other software) is permitted, provided that:
- It is clearly stated in the documentation
- It is clearly stated in source comments
- The code may NOT be used to develop a RAR (WinRAR) compatible archiver

Permitted Uses:

The unRAR sources may be used in any software to handle RAR
archives without limitations free of charge, but cannot be used
to re-create the RAR compression algorithm, which is proprietary.

What You CAN Do:

Use compiled files under GNU LGPL rules (unRAR license has minimal restrictions on compiled files)
Link compiled files to LGPL programs
Fix bugs in source code and use the compiled fixed version
Decompress RAR archives
Handle RAR archives in your software

What You CANNOT Do:

Use unRAR sources to re-create the RAR compression algorithm
Develop a RAR (WinRAR) compatible archiver
Charge fees for distributing unRAR without written permission from Alexander Roshal

Disclaimer

THE RAR ARCHIVER AND THE UNRAR UTILITY ARE DISTRIBUTED "AS IS".
NO WARRANTY OF ANY KIND IS EXPRESSED OR IMPLIED. YOU USE AT 
YOUR OWN RISK. THE AUTHOR WILL NOT BE LIABLE FOR DATA LOSS, 
DAMAGES, LOSS OF PROFITS OR ANY OTHER KIND OF LOSS WHILE USING
OR MISUSING THIS SOFTWARE.

BSD 3-Clause License

BSD 3-Clause License (LZFSE and ZSTD)

The following components use the BSD 3-clause License:

LZFSE Decompression

File: CPP/7zip/Compress/LzfseDecoder.cpp
Origin: Derived from LZFSE compression library by Apple Inc.
Copyright:
- (c) 2015-2016, Apple Inc. All rights reserved.
- (c) 2023-2026 Igor Pavlov.

ZSTD Decompression

File: C/ZstdDec.c
Origin: Developed using original zstd decoder code as reference
Original Developer: Facebook Inc.
Copyright:
- (c) Facebook, Inc. All rights reserved.
- (c) 2023-2026 Igor Pavlov.

License Text

Redistribution and use in source and binary forms, with or without 
modification, are permitted provided that the following conditions 
are met:

1. Redistributions of source code must retain the above copyright 
   notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright 
   notice, this list of conditions and the following disclaimer in 
   the documentation and/or other materials provided with the 
   distribution.

3. Neither the name of the copyright holder nor the names of its 
   contributors may be used to endorse or promote products derived 
   from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 
ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
POSSIBILITY OF SUCH DAMAGE.

BSD 2-Clause License

BSD 2-Clause License (XXH64)

XXH64 Hash Function

File: C/Xxh64.c
Origin: Derived from original XXH64 code by Yann Collet
Copyright:
- (c) 2012-2021 Yann Collet.
- (c) 2023-2026 Igor Pavlov.

License Text

Redistribution and use in source and binary forms, with or without 
modification, are permitted provided that the following conditions 
are met:

1. Redistributions of source code must retain the above copyright 
   notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright 
   notice, this list of conditions and the following disclaimer in 
   the documentation and/or other materials provided with the 
   distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 
ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
POSSIBILITY OF SUCH DAMAGE.

Public Domain Components

LZMA SDK

The LZMA SDK is written and placed in the public domain by Igor Pavlov.

Download: http://www.7-zip.org/sdk.html
License: Public domain (no restrictions)
Usage: Can be freely used in any project

Other Public Domain Files

Some files in the 7-Zip source are explicitly marked as public domain in their source code headers.

Compilation Options for License Compliance

Excluding RAR Code

If the unRAR license restrictions are not compatible with your project’s requirements, you can exclude RAR-related code during compilation:

RAR Exclusion Options

Option 1: DISABLE_RAR_COMPRESS=1Removes “not fully free” RAR decompression codecs from compilation.

make -f makefile.gcc DISABLE_RAR_COMPRESS=1

Capabilities with this option:

Open RAR archives
List files in RAR archives
Extract files that are stored without compression

Limitations:

Cannot decompress compressed files from RAR archives

Option 2: DISABLE_RAR=1Completely removes all RAR-related code from compilation.

make -f makefile.gcc DISABLE_RAR=1

Limitations:

No RAR archive support at all

License Compatibility Summary

When distributing 7-Zip or incorporating it into your project, ensure you comply with ALL applicable licenses:

GNU LGPL for most code
GNU LGPL + unRAR restriction for RAR decompression
BSD 3-clause for LZFSE and ZSTD decoders
BSD 2-clause for XXH64 hash
Public domain for LZMA SDK

The unRAR restriction is the most restrictive component and may not be compatible with some free-software licenses.

Additional Resources

License.txt - Complete license documentation
copying.txt - Full GNU LGPL license text
unRarLicense.txt - Complete unRAR license
GNU LGPL: http://www.gnu.org/

Contact

For licensing questions or permissions: Igor Pavlov
http://www.7-zip.org

Building from Source

SDK & Integration

Contributing

License Information

Overview

License Summary by Component

GNU LGPL License

unRAR License Restriction

Files Affected

unRAR License Terms

Disclaimer

BSD 3-Clause License

LZFSE Decompression

ZSTD Decompression

License Text

BSD 2-Clause License

XXH64 Hash Function

License Text

Public Domain Components

LZMA SDK

Other Public Domain Files

Compilation Options for License Compliance

Excluding RAR Code

License Compatibility Summary

Additional Resources

Contact

​Overview

​License Summary by Component

​GNU LGPL License

​unRAR License Restriction

​Files Affected

​unRAR License Terms

​Disclaimer

​BSD 3-Clause License

​LZFSE Decompression

​ZSTD Decompression

​License Text

​BSD 2-Clause License

​XXH64 Hash Function

​License Text

​Public Domain Components

​LZMA SDK

​Other Public Domain Files

​Compilation Options for License Compliance

​Excluding RAR Code

​License Compatibility Summary

​Additional Resources

​Contact

Overview

License Summary by Component

GNU LGPL License

unRAR License Restriction

Files Affected

unRAR License Terms

Disclaimer

BSD 3-Clause License

LZFSE Decompression

ZSTD Decompression

License Text

BSD 2-Clause License

XXH64 Hash Function

License Text

Public Domain Components

LZMA SDK

Other Public Domain Files

Compilation Options for License Compliance

Excluding RAR Code

License Compatibility Summary

Additional Resources

Contact