What is a ZIP archive?

A ZIP archive is a compressed file format that bundles multiple files and folders into a single container. Created in 1989 by Phil Katz, ZIP has become the most widely used archive format across all operating systems. The format uses lossless compression algorithms (primarily DEFLATE) to reduce file sizes while preserving all original data perfectly. ZIP files maintain the directory structure, file names, timestamps, and other metadata of the archived content, making them ideal for file distribution, backup, and storage optimization.

How does ZIP compression work?

ZIP compression analyzes file content to identify and eliminate redundant data patterns. The DEFLATE algorithm combines two techniques: LZ77 (replacing repeated sequences with shorter references) and Huffman coding (assigning shorter codes to frequently occurring patterns). Compression ratios vary significantly based on file types—text files and uncompressed images may compress to 10-20% of their original size, while already-compressed formats like JPEG or MP4 show minimal reduction. The compression ratio displayed by archive viewers indicates the percentage of space saved compared to the original uncompressed size.

Tool description

This tool allows you to browse and inspect the contents of ZIP archive files directly in your browser without extracting them. Upload any ZIP file to view its complete file structure, including nested folders and files at any depth. The tool displays comprehensive archive metadata such as total file count, folder count, compressed and uncompressed sizes, and overall compression ratio. You can navigate through the archive's directory tree, examine individual file details, and download specific files without extracting the entire archive.

Features

  • Browser-based processing: All operations happen locally in your browser—no files are uploaded to any server, ensuring complete privacy
  • Hierarchical file browser: Navigate through nested folder structures with an expandable tree view that supports unlimited depth
  • Detailed metadata display: View archive name, total files, total folders, uncompressed size, compressed size, and compression ratio
  • Individual file extraction: Download specific files from the archive without needing to extract everything
  • Human-readable file sizes: All sizes are displayed in appropriate units (bytes, KB, MB, GB) for easy understanding

Use cases

  • Quick archive inspection: Preview ZIP contents before deciding whether to extract the full archive, saving time and disk space
  • Selective file extraction: Download only the specific files you need from a large archive without extracting everything
  • Archive verification: Confirm that a ZIP file contains the expected files and folder structure before distribution or backup
  • Storage analysis: Analyze compression efficiency and identify which files contribute most to archive size
  • Email attachment preview: Quickly check the contents of ZIP attachments without downloading and extracting them locally