What Information Is in the 7-Zip Properties Window?

The file properties window in 7-Zip provides a comprehensive breakdown of technical metadata for individual files, folders, and compressed archives. Accessing this dialog by selecting an item and clicking the "Info" or "Properties" button (or pressing Alt+Enter) inside the 7-Zip File Manager displays essential file system details alongside advanced compression and cryptographic data. This overview breaks down each category of information visible in the window, helping you understand the exact metrics 7-Zip reports.

Basic File and System Attributes

When viewing standard uncompressed files or folders, the properties window displays foundational file system information:

  • Name and Path: The full file name, file extension, and its absolute path within the directory structure.
  • Size: The true uncompressed size of the file, measured in bytes as well as readable units (KB, MB, or GB).
  • Packed Size: The physical size on the disk (cluster allocation) or the size the file occupies after compression.
  • Timestamps: Precise dates and times for when the file was Created, Last Modified, and Last Accessed.
  • Attributes: Standard file flags such as Archive (A), Read-Only (R), Hidden (H), System (S), or Directory (D).
  • Links: The count of hard links pointing to the specific file, if supported by the file system (e.g., NTFS).

Compression and Archive Metadata

When examining a compressed archive (such as .7z, .zip, .tar, or .rar) or files housed within one, 7-Zip exposes detailed compression parameters:

  • Type: The specific container format (e.g., 7z, zip, cab, iso).
  • Method: The compression algorithm applied to the contents, such as LZMA, LZMA2, Deflate, PPMd, or BZip2.
  • Solid Status: Indicates whether the archive was built using "Solid" compression (Solid = + or -), which pools multiple files together to increase the compression ratio.
  • Blocks: The number of compressed solid blocks into which the data is grouped.
  • Dictionary Size: The memory buffer size used during compression (e.g., 16 MB, 64 MB), which indicates the system memory required for decompression.
  • Folders and Files Count: The total number of subdirectories and individual files contained inside the archive.
  • Encrypted: Specifies whether files or archive headers are password-protected with encryption standards like AES-256 or ZipCrypto.

Checksum and Integrity Information

7-Zip calculates and displays mathematical checksums that allow you to verify file integrity and detect data corruption:

  • CRC (Cyclic Redundancy Check): A 32-bit CRC hash (CRC32) calculated for the file payload. This is primarily used to detect accidental corruption during storage or transmission.
  • Characteristics: Internal flags that show whether an archive contains 64-bit extensions (Zip64), alternative data streams, or custom headers.

Extended File System and Host Details

For advanced formats and multi-platform archives, 7-Zip captures environment-specific attributes:

  • Host OS: Identifies the operating system under which the archive was generated (e.g., Windows, FAT, Unix).
  • Embedded Stubs: Information regarding whether an archive is a self-extracting executable (SFX).
  • Alternate Streams: Size and count of any NTFS Alternate Data Streams (ADS) packaged with the file.