Novus Convert
Convert files
Archive format

7Z converter

A .7z file is a 7-Zip archive built around the LZMA family of compressors, which routinely beat ZIP's ratios by 30-50% on typical data. It is the open, free-software answer to high-compression archiving.

Private for supported formats — processed in your browser

Convert supported files

Runs on your device

Drop 7Z files here

Batch files can each use a different output. Nothing uploads for local conversions.

Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.

Where 7Z comes from

Igor Pavlov released 7-Zip and the 7z format in 1999, introducing LZMA — a dictionary compressor with vastly larger match windows than DEFLATE. LZMA2 later improved multithreading, and the LGPL-licensed SDK carried the algorithm into xz, installers, and package managers.

How 7Z works

  • Solid compression concatenates files into one stream before compressing, exploiting redundancy between files at the cost of random access.
  • Dictionary sizes can reach gigabytes, versus DEFLATE's 32 KB window, capturing long-range repetition.
  • AES-256 encryption can additionally encrypt the header, hiding even the list of filenames.
  • The container is codec-agnostic, supporting LZMA, LZMA2, PPMd, BZip2, and preprocessing filters like BCJ for executables.

When to use 7Z

  • Backups where every saved gigabyte counts.
  • Distributing large datasets, game mods, and disk images.
  • Archiving many similar files — logs, source trees — where solid mode shines.
  • Encrypted archives whose file listing must also stay private.

Strengths and limitations

Strengths

  • Best-in-class compression among mainstream archive formats.
  • Open format with LGPL reference code and no licensing strings.
  • Strong encryption including hidden headers.
  • LZMA2 compresses in parallel across cores.

Limitations

  • Historically no OS opened it out of the box, so recipients often need 7-Zip or a similar app.
  • Solid archives make extracting a single file slow, and damage tends to spread across the solid block.
  • High compression settings are markedly slower than creating a ZIP.

Compatibility

7-Zip is the reference tool on Windows, with Keka and The Unarchiver covering macOS and p7zip on Linux. Windows 11's 2023 update added native .7z extraction via libarchive — the same library, compiled to WebAssembly, that lets this site unpack 7z archives in the browser.

Preserves modification times by default, with creation and access times plus file attributes available as optional flags at creation.

Convert 7Z to another format