Catpaq

GUI explorer for ZPAQ archives powered by zpaqfranz. Browse versions, extract files, test integrity and add new content — no installation required.

ZPAQ is one of the best compression formats around — great compression ratio, incremental backups, full version history. The catch: it has no official GUI. catpaq fixes that. Drop it next to zpaqfranz, open an archive, and you're done.

Features

• Browse any ZPAQ archive — see all files and folders, with full version history
• Time machine — navigate between archive snapshots and extract any past version of a file
• Integrity test — verify your archive with real-time progress and ETA, results shown directly in the log
• Add files — select files and folders from the built-in file explorer and add them to any archive
• Extract — extract single files, folders, or everything, with GUI destination picker
• Encrypted archives — supports AES and Franzen password protection
• Filter & search — quickly find files inside large archives
• Hash calculation — CRC32, SHA256, BLAKE3, XXH3 and many more, with clipboard copy on single file
• Portable — no installer, no registry, no admin rights needed (unless you want file associations)
• Cross-platform — runs on Windows, Linux and macOS (work in progress)

Requirements

Catpaq is a front-end: it needs the zpaqfranz executable to do the actual work, and will offer to download it for you (on Windows).
BTW zpaqfranz official repository

Installation

No installer required.

1. Download the latest release from the Releases page
2. Unzip the archive to any folder you like
3. Place zpaqfranz (or zpaqfranz.exe on Windows) in the same folder
4. Run catpaq.exe (Windows) or catpaq (Linux/macOS)

(Windows) To open .zpaq files directly from your file manager, run catpaq as Administrator and use Settings → Associate .zpaq and .zpaq.franzen.

Screenshots

Archive browser	Integrity test	File explorer

How it works

Catpaq is a GUI layer over zpaqfranz.
Every action — listing, extracting, testing, adding — translates into a zpaqfranz command that runs in the background.
Output is streamed live into the Log tab, so you always see exactly what's happening.

The Add tab is a built-in file explorer: navigate your drives, select files, and send them to any archive in a few clicks.
No drag-and-drop from an external window needed.

Building from source

Catpaq is written in Free Pascal / Lazarus. To build it yourself:

1. Install Lazarus (tested with 4.x)
2. Clone this repository
3. Open catpaq.lpr in the Lazarus IDE
4. Build → Compile

Almost no external dependency

Credits

Catpaq is a front-end for zpaqfranz by Franco Corbelli, which is itself based on ZPAQ by Matt Mahoney. All the heavy lifting — compression, encryption, verification — is done by zpaqfranz.

License

MIT — see LICENSE for details.