7

.77-Zip Archive

Igor Pavlov · 1999

Developer
Igor Pavlov
Category
Archives
MIME Type
application/x-7z-compressed
First Released
1999
Open Format
Yes
File Signature
37 5A BC A0
At a Glance
.7
7-Zip Archive

.7z is a file format for compressed archives, offering superior compression ratios and strong encryption, often outperforming traditional ZIP files.

Reviewed on May 15, 2026
Compression
Compressed
Transparency
No
Editability
Low
Best for
Maximum compression

Key Features

  • Superior compression ratios using LZMA/LZMA2.
  • Strong AES-256 encryption support.
  • Support for solid archiving to reduce redundancy.
  • Ability to store multiple files and directory structures.

Best For

  • Achieving the smallest possible file size for archives.
  • Compressing large collections of text or code files.
  • When strong encryption is a primary requirement.
  • Distributing large software or data sets.

Less Ideal For

  • Quick, simple sharing where compatibility with basic ZIP tools is needed.
  • Archiving very small, single files where compression gains are minimal.
  • Situations requiring widespread compatibility without dedicated software.
  • When editability of individual files within the archive is frequently required without extraction.

Common Use Cases

  • Compressing large software distributions for download.
  • Archiving personal data to save disk space.
  • Securely transferring sensitive files online.
  • Bundling multiple files for easier distribution.

How to Open It

  1. Install 7-Zip (Windows) or Keka (macOS), which natively support .7z files.
  2. Use built-in archive utilities on Linux (e.g., `p7zip-full` package).
  3. Right-click on the .7z file in your file explorer and select 'Extract' or 'Open Archive'.
  4. Install a compatible third-party app on mobile devices like Files (iOS) or Solid Explorer (Android).

What is a .7 file?

The .7z file format is a highly efficient archive file format known for its excellent compression ratios. It uses the LZMA and LZMA2 compression algorithms, which can often achieve smaller file sizes compared to older formats like ZIP. This makes it ideal for storing or transferring large amounts of data where space is a concern. The format also supports strong encryption, making it a secure choice for sensitive files. It's widely supported by various archiving tools, with 7-Zip being the most prominent.

Programs That Open .7 Files

PlatformProgram
Windows7-ZipFreeOfficial
PeaZipFree
WinRARPaid
macOSKekaFree
The UnarchiverFree
PeaZipFree
Linux7zFreeOfficial
PeaZipFree
ArkFree
AndroidSolid ExplorerFree
RARPaid
iOSiZipFree
Files appFreeOfficial

How to Convert .7 Files

FormatMethod
.ZIP7-Zip, PeaZip, Online Converters
.TAR7-Zip, PeaZip, Command Line (tar)

Common Problems with .7 Files

⚠️ Cannot open .7z file without dedicated software.
Install a compatible archiver like 7-Zip (Windows), Keka (macOS), or `p7zip-full` (Linux).
⚠️ Archive is corrupted and cannot be extracted.
Attempt to use the 'test' function in your archive software or try to repair the archive if supported.
⚠️ Extremely slow extraction or compression.
Ensure your system meets the recommended specifications for the chosen compression algorithm (LZMA/LZMA2 can be CPU intensive) and consider using a faster algorithm like Deflate if speed is prioritized over size.

Frequently Asked Questions

Is .7z better than .zip?

.7z generally offers better compression ratios than .zip, meaning it can create smaller files. It also supports stronger encryption. However, .zip has wider native support across operating systems.

Can I encrypt a .7z archive?

Yes, the .7z format supports strong AES-256 bit encryption for both the file data and optionally the file names within the archive.

What's the difference between LZMA and LZMA2?

LZMA2 is an improved version of LZMA, designed for better multi-core processor utilization and potentially higher compression ratios on certain types of data.

Technical Details

The .7z format is a container that can hold multiple files and directories, typically compressed using LZMA or LZMA2 algorithms for high compression. It supports AES-256 encryption for both files and headers, and can also incorporate solid archiving features for better efficiency. Its file signature starts with the bytes '0x37 0x5A 0xBC 0xA0'.

Did You Know?

The .7z format was developed by Igor Pavlov and is the native format for the popular 7-Zip file archiver.
Its distinct file signature, '7z', is clearly visible in hexadecimal editors and is followed by specific version and header information.

Security Information

The .7z format supports AES-256 encryption, which is a robust standard for securing data. Ensure you use a strong password if encrypting sensitive files. Be cautious when downloading .7z files from untrusted sources, as they could contain malware, just like any other file type.

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