Online Zipping Tool

Purpose & User Intent: This tool enables in-browser ZIP creation and packaging without server uploads, enabling individuals, students, developers, and teams to assemble multiple files into a ZIP archive quickly and privately. It is used when privacy is paramount, network bandwidth is limited, or offline packaging is required. Typical scenarios include backing up local projects, sharing datasets via email or cloud storage, or preparing multi-file bundles for demonstrations. Users can perform multiple packaging sessions in a single browser tab, without creating accounts or sending data to external services.
Core Logic & Features: The tool streams selected inputs into a ZIP container using a high-performance client-side compression library (WebAssembly or optimized JS). Required features include: file selection & queuing, in-browser compression, support for ZIP64, option to enable password protection, and optional split-archive creation with a chosen part size. Optional/advanced features include preserving file order, timestamps, and file comments (if supported), configurable compression level, and integrity verification via CRC32 post-compression. Output formats include a single archive or a multi-part set with consistent naming. The tool prioritizes privacy, speed, and deterministic results across major browsers.
Inputs & Outputs: Inputs: files (name, size, type, last-modified), zip64_enabled (bool), password (string, optional), split_size_bytes (int, optional). Outputs: archive_blob/URL or downloadable files; mime type application/zip; if split, outputs multiple parts with names archive.part1.zip etc.; metadata JSON could be generated but not required. Validation: at least one file, split_size positive, password length restrictions, and file sizes within browser capabilities.
Algorithms & Calculations: Uses ZIP container algorithm with DEFLATE compression; ZIP64 extension used when size exceeds 4 GB; CRC32 checksums ensure integrity; if password is provided, encryption is applied per ZIP spec; progress estimation is computed from input sizes and compression ratios; processing is confined to the client. Error & Edge Cases: Invalid inputs (no files) cause a clear, deterministic error; very large archives may trigger memory or time constraints; unsupported file types are skipped with a log entry; encrypted archives require a password for extraction; partial failures are reported with actionable guidance. Industry/Region & Localization: ZIP is a global standard; the tool adheres to ZIP and ZIP64 specifications and operates with browser-local data handling; timestamps follow file metadata; no server data retention; locale considerations apply to date/time metadata presentation where applicable. Assumptions & Exclusions: Assumes user grants access to local files; not a cloud storage service; does not convert to non-ZIP formats unless added as a feature; does not upload data to a remote server; does not support real-time collaboration.