Convert B1 to ZIP

A recipient, operating system, or application may accept ZIP archives but not B1 files. The dependable conversion method is to extract the B1 archive and create a new ZIP archive from the extracted files.

What the B1 format is

B1 is the native archive format associated with B1 Free Archiver. A .b1 file can contain multiple files and folders compressed into one archive, and it may be password-protected. B1 archives are mainly encountered when B1 Free Archiver is used to package or distribute software, documents, or other collections of files.

What the ZIP format is

ZIP is a widely supported archive format available through Windows File Explorer, macOS Finder, Linux archive managers, 7-Zip, and many mobile applications. It combines files and folders into one package and can compress them, although the resulting size depends on the contents and compression settings. ZIP is commonly required for uploads, email attachments, software distribution, and exchange with systems that do not support B1.

Creating a ZIP does not convert the B1 container byte-for-byte. It stores the files extracted from the B1 archive in a new container.

How to convert B1 to ZIP

Using B1 Free Archiver and 7-Zip

1. Install B1 Free Archiver from the official B1 website and 7-Zip from 7-zip.org. B1 Free Archiver is used to read and extract the B1 archive; 7-Zip is used here to create the ZIP.
2. Open source.b1 in B1 Free Archiver. Enter the archive password if requested.
3. Choose Extract or Extract to and select a temporary destination. Check that the extracted location contains the expected files and folder structure.
4. Select the extracted files and folders that should go into the ZIP. Select the top-level folder itself if that folder must appear inside the ZIP; select its contents instead if the ZIP should open directly to those files.
5. Right-click the selection and choose 7-Zip → Add to archive....
6. Set Archive format to zip, enter a destination such as converted.zip, and select OK.

7-Zip can perform the packaging from a command line after extraction. To place the contents of a directory in the archive, run:

7z a -tzip converted.zip extracted-folder\*

To place the directory itself at the ZIP's top level, run the command from its parent directory and name the directory rather than using the wildcard:

7z a -tzip converted.zip extracted-folder

Using built-in operating-system tools

After extraction, Windows users can select the files or folder in File Explorer and choose Compress to ZIP file. In macOS Finder, select the items and choose Compress. Linux users can use the ZIP option in their desktop archive manager or install 7-Zip if their desktop does not provide one.

Using an online service

B1 Online Archiver can extract a B1 archive in a browser. Upload source.b1, provide its password if required, download the extracted files, and create the ZIP locally with the operating system or 7-Zip. Online services may impose file-size, filename, or retention limits and require transferring the archive to a third-party server. Do not upload confidential, personal, copyrighted, or legally restricted material unless the service is approved for that data.

Compatibility and quality limitations

The new ZIP normally preserves the contents of the extracted files, but it does not automatically preserve B1-specific compression settings, archive comments, encryption, or all container metadata. File permissions, timestamps, symbolic links, and other filesystem attributes can also change during extraction or repackaging.

If the B1 archive is split into multiple volumes, keep every volume in the same directory and open the first volume in B1 Free Archiver. Extraction cannot succeed if a required part is missing. A password used for the B1 archive does not automatically protect the ZIP; configure ZIP encryption separately when needed. ZIP encryption compatibility varies, so a ZIP using AES encryption may require 7-Zip or another compatible archiver rather than the built-in tools in some operating systems.

Open the completed ZIP with 7-Zip or the intended recipient application and verify representative files, folder paths, filenames, file sizes, and any password-protected content before deleting the extracted working copy.