Convert TAR to 7Z — Free Online Converter

TAR (Tape Archive) is Unix's foundational file-bundling format from 1979, storing files and directories in a single uncompressed stream with full preservation of permissions, ownership, symbolic links, and timestamps. TAR applies no compression — it is purely an archival container. 7Z is the open-source archive format from Igor Pavlov's 7-Zip project, using LZMA and LZMA2 algorithms that deliver the highest general-purpose compression ratios available.

Converting TAR to 7Z wraps your uncompressed Unix file bundle in highly efficient LZMA2 compression. This dramatically reduces the archive size — a 500 MB TAR file can compress to 50-150 MB as 7Z depending on content type. The conversion is essential when you need to minimize storage footprint or transfer time for large tar archives.

Uncompressed TAR files are space-inefficient for storage and slow to transfer over networks. A typical source code tree that occupies 200 MB as a plain .tar compresses to 20-40 MB as .7z, saving 80-90% of storage space. For archival repositories holding thousands of tarballs, the cumulative savings translate directly to lower cloud storage costs.

7Z also provides AES-256 encryption that TAR lacks entirely. Converting TAR to 7Z lets you add strong encryption to archives that were previously stored unprotected. The solid archive mode further improves compression by exploiting redundancy across files — particularly effective on source code, log files, and configuration bundles where many files share similar content.

The TAR archive is read sequentially, extracting file entries by parsing 512-byte header blocks (containing filename, size, permissions, timestamps) followed by the raw file data. All extracted files are placed in a temporary directory preserving the original hierarchy. The 7-Zip compressor then packs the file tree into a 7Z archive using LZMA2 compression with solid mode enabled by default (grouping files for cross-file redundancy exploitation). Dictionary size is automatically scaled based on available memory — up to 64 MB for maximum compression on large archives.