100% Client-Side Archive Converter

Convert ZIP to 7Z

Convert ZIP archives to the highly efficient 7Z compression format without uploading anything to a server.

Your files never leave your device. Conversion happens entirely inside your browser.
Select ZIP
Convert to 7Z
Download

Drag & drop a .zip file here, or browse

Max size: 500 MB (Desktop)

Why Use Client-Side 7Z?

Ultimate Data Privacy

No servers, no cloud storage, no logs. Your files are processed entirely within a browser Web Worker sandbox.

High Compression Ratio

7Z archives powered by LZMA compression drastically reduce file sizes compared to standard ZIP archives.

Unicode & Folder Fidelity

Preserves complete directory hierarchies and special character filenames exactly as originally archived.

Zero Memory Leaks

Automatically revokes memory allocations, unmounts virtual files, and terminates workers upon task completion.

System Specifications:

  • • Engine: WebAssembly (7z-wasm / Emscripten)
  • • Concurrency: Non-blocking Web Worker
  • • Max Desktop Limit: 500 MB
  • • Max Mobile Limit: 100 MB

Compatible with Chrome, Edge, Firefox, and Safari on desktop and mobile devices.

Processing and privacy

What is ZIP to 7Z?

ZIP to 7Z processes your files securely in your browser. No installation or registration is required.

The tool runs on your device, so your files never need to be uploaded to our servers.

Key Features

Browser-Based Conversion

Convert files directly in your browser without uploading to any server.

High Compression Ratio

7Z format provides superior compression compared to ZIP.

Fast Processing

Powered by WebAssembly for near-native performance.

Completely Free

No registration, no limits, totally free to use.

How It Works

  1. 1

    Upload File

    Select or drag and drop your file into the tool.

  2. 2

    Process

    Choose your settings and start processing.

  3. 3

    Download

    Download the processed file directly to your device.

Supported Formats

Supports the standard formats listed by this tool.

Privacy & Security

Your files stay in your browser and are not uploaded to our servers.

Frequently Asked Questions

Frequently asked questions about ZIP to 7Z.

Yes. This tool is free and requires no registration.

No. Processing happens locally in your browser, so your files stay on your device.

The practical limit depends on your device's available memory.

Yes. The tool works in modern desktop and mobile browsers.

Current versions of Chrome, Safari, Firefox, and Edge are supported.