RunConvert

BZ Converter

Convert files to and from BZ online for free. Fast, secure, and high-quality file conversion with no sign-up or software required.

Free to useNo file stored beyond 1 hourEncrypted over TLS 1.2/1.3No watermarks

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How it works

Three steps to your converted file

Everything happens in your browser tab - upload, pick a format, download. The heavy lifting runs on our servers.

01

Upload your file

Drag and drop, click to browse, or paste a URL. Batches take up to 20 files at once - 230+ input formats across video, audio, image, document, and archive types.

02

Choose an output format

Pick from over a hundred output formats. Filter by category or search by name - every option is open to everyone, no account needed.

03

Convert & download

Hit Convert and grab your download link moments later. Originals are erased when the job completes; results are cleared within about an hour.

What is a BZ file?

The BZ file extension represents a compressed archive created by the original bzip utility, developed by Julian Seward in 1996. This format utilizes the Burrows-Wheeler Transform (BWT) for block-sorting text permutation, followed by Move-to-Front (MTF) transforms and arithmetic coding to achieve high-density lossless compression. The BZ format is the predecessor to the more standard bzip2 (.bz2); it was deprecated and superseded shortly after release due to patent concerns surrounding the use of arithmetic coding, which was subsequently replaced by Huffman coding in bzip2. Unlike ZIP archives, BZ files typically compress a single stream or file and do not natively support directory archiving without a container format like TAR.

How to open a BZ file

Modern operating systems do not provide native decoding support for the legacy BZ format due to its obsolescence and the prevalence of bzip2. To extract data from a BZ file, users require third-party file compression software capable of handling legacy block-sorting algorithms. 7-Zip is the recommended utility for Windows environments due to its comprehensive backward compatibility, while macOS users should utilize The Unarchiver. In Linux and Unix-like environments, the standard bzip2 command-line utility often retains backward compatibility to decompress these files using the -d flag.

BZ Technical Info

Full Name
Bzip Compressed File
Developed By
Julian Seward
Initial Release
1996
MIME Type
application/x-bzip

Why RunConvert

The fastest way to convert any file

Purpose-built for speed, privacy, and breadth of format support.

3,000+ conversions supported

Every popular and niche format covered - video, audio, image, document, archive and more. New formats added regularly.

Fast, cloud-powered

No queue, no waiting. Files are processed on high-performance servers and returned in seconds, even for large files.

Secure & private

Encrypted in transit and never shared with anyone. Uploads are erased the moment your job completes, and results shortly after.

Free - no account needed

Convert without creating an account - no credit card, no trial clock. Sign in only if you want history and higher daily limits.