Novus Convert
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Archive format

GZ converter

A .gz file is a single data stream compressed with gzip. Note the singular: gzip compresses exactly one file, so bundling several requires wrapping them in a tar first — which is why .tar.gz is everywhere while a multi-file bare .gz simply does not exist.

Private for supported formats — processed in your browser

Convert supported files

Runs on your device

Drop GZ 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 GZ comes from

Jean-loup Gailly and Mark Adler wrote gzip for the GNU Project in 1992, purpose-built to replace Unix compress, whose LZW algorithm was encumbered by the Unisys patent. Its DEFLATE stream and container were codified in RFC 1951 and RFC 1952 in 1996.

How GZ works

  • DEFLATE combines LZ77 matching within a 32 KB window with Huffman coding — the same algorithm inside ZIP and PNG.
  • The 10-byte header can carry the original filename and modification time; a CRC-32 and length trailer verify the payload.
  • Compression levels 1 through 9 trade speed for ratio, while decompression speed stays roughly constant.
  • Streams are concatenable: appending one .gz to another yields a valid file that decompresses to both payloads in sequence.

When to use GZ

  • Compressing single large files such as logs, SQL dumps, and disk images.
  • HTTP response compression (Content-Encoding: gzip) on virtually every web server.
  • The compression half of the .tar.gz pairing.
  • Automatic log rotation via logrotate and similar tools.

Strengths and limitations

Strengths

  • Very fast with modest memory needs.
  • Universally available on Unix systems since the early 1990s.
  • Fully streamable — compresses and decompresses in a pipe.
  • Stable, patent-free, and exhaustively documented.

Limitations

  • Single-stream only; it cannot bundle files by itself.
  • Middling ratios next to xz, 7z, or zstd.
  • No encryption and only CRC-32 integrity checking.

Compatibility

gzip and gunzip ship with every Unix-like OS, browsers transparently decompress gzip-encoded web traffic, and Windows covers it through 7-Zip or the bundled bsdtar. In-browser JavaScript handles it natively too — fflate inflates and deflates gzip streams client-side.

The header optionally embeds the source filename and timestamp, restorable with gunzip -N; permissions are not stored at all — in a tarball, that is the inner tar's job.

Convert GZ to another format