Skip to main content

7z

PropertyValue
descriptionNative archive format of 7-Zip, designed for high compression, strong encryption, and flexible archival features.
tagsref
rating

7z is the native archive format of 7-Zip.

It is designed for high compression, strong encryption, and flexible archival features such as solid compression, header compression, and support for very large files.

What it does​

The 7z format is used to package one or more files into a single compressed archive.

It is commonly used to:

  • Reduce file size with strong compression
  • Bundle many files into one archive
  • Protect archives with AES-256 encryption
  • Split archives into multiple volumes
  • Preserve directory structure during storage or transfer

Core concepts​

Format vs application​

7z is the file format.

7-Zip is the application most commonly used to create and extract it.

High compression​

The 7z format is best known for high compression ratios compared with more compatibility-focused formats such as ZIP.

In practice, 7-Zip commonly uses LZMA or LZMA2 methods with the 7z container.

Strong archive features​

The format supports features such as:

  • AES-256 encryption
  • Solid compression
  • Unicode file names
  • Large file and archive sizes
  • Header compression and header encryption

Common use cases​

  • Creating smaller archives for storage or transfer
  • Packaging large project folders into a single file
  • Encrypting sensitive file collections
  • Distributing multi-part archives
  • Using stronger compression than ZIP when compatibility is not the main priority

Practical notes​

  • The 7z format is usually chosen when compression ratio matters more than broad built-in OS compatibility.
  • ZIP is still more universally supported out of the box, especially on consumer systems.
  • 7z archives are most closely associated with 7-Zip, especially on Windows.
  • A .7z file is an archive container, not a single compression algorithm by itself.

Sources Used​

Frequently Asked Questions​

Is 7z the same as 7-Zip?​

No. 7z is the archive format. 7-Zip is the software most commonly used to work with that format.

Is 7z better than ZIP?​

Not universally. 7z is often better for stronger compression and advanced archive features, while ZIP is often better for compatibility.

Can 7z archives be encrypted?​

Yes. The 7z format supports AES-256 encryption, including encrypted headers.