TAR to TB2 Converter

How to Convert TAR to TB2 Online

1. Upload Your TAR File: Drag and drop or click "+ Add Files" to select one or more .tar archives. Batch upload is supported — drop multiple TARs in one go.
2. Choose Single Archive or Individual Archives: Under "Combine?" pick Single Archive to bundle every uploaded TAR's contents into one .tb2 file, or Individual Archives to produce a separate .tb2 for each input TAR. Default is Single Archive.
3. Review Advanced Options (Optional): Defaults apply standard bzip2 compression (Burrows-Wheeler transform with the default 900 kB block size, the same setting bzip2 -9 uses on the command line). Most users can keep defaults.
4. Convert and Download: Click "Convert" and grab your .tb2 file. Files stay private — uploads are processed on our servers and removed automatically after conversion.

Why Convert TAR to TB2?

A .tar file is just a container — it packages multiple files into one stream without any compression, so the archive is roughly the same size as the sum of its contents. Wrapping that TAR in bzip2 (producing .tar.bz2, also written as .tbz2, .tb2, or .tbz) shrinks it significantly, especially for text-heavy payloads like source code, log files, and configuration trees. The .tb2 extension is simply a shorter alias for .tar.bz2 — same bytes, same algorithm, just a four-character filename suffix that survives older filesystems that disliked double extensions.

• Smaller backups and transfers — bzip2 typically produces files 15-30% smaller than the equivalent gzip (.tar.gz) for text-dominant data, and dramatically smaller than the raw .tar. That matters when you're rsyncing nightly backups, attaching a project snapshot to an email, or pushing release tarballs over metered bandwidth.
• Source code distribution — many UNIX/Linux upstream projects (GNU coreutils, the Linux kernel mirrors, older Debian source packages) historically ship as .tar.bz2 because the asymmetric tradeoff favors the publisher: compress once, decompress many times.
• Long-term archival on disk — when storage is the constraint and you'll rarely re-open the archive, the slower bzip2 compression pass is a one-time cost that buys you persistent space savings.
• Compatibility with Linux/macOS tooling — .tb2 opens natively with tar -xjf file.tb2 on every modern UNIX-like system, and with The Unarchiver, Keka, or 7-Zip on macOS and Windows. No proprietary tooling required.
• Preserves POSIX metadata — unlike ZIP, TAR (and therefore TB2) keeps UNIX permissions, ownership, symlinks, and timestamps intact, which matters when you're shipping a directory tree that needs to be restored exactly.
• Single-file payload — bundling many small files into one .tb2 avoids the per-file overhead of separate transfers and dodges the "too many small files" performance cliff on network filesystems and cloud object stores.

TB2 vs TGZ vs TAR — Format Comparison

Bzip2 Block Size Guide

Bzip2 splits input into blocks of 100-900 kB before compressing. Larger blocks compress better but use more RAM. Our default uses the maximum block size (equivalent to bzip2 -9), which is what almost every distributor ships.

Frequently Asked Questions

Is .tb2 the same as .tar.bz2 and .tbz2?

Yes — bit-for-bit identical. The extensions .tar.bz2, .tbz2, .tb2, and .tbz all describe a TAR archive compressed with bzip2. They differ only in the filename suffix. .tb2 and .tbz were introduced for filesystems (historically Windows 8.3, some older FAT variants, and certain mainframe transfer tools) that disliked double extensions or capped the suffix at three characters. Any tool that opens one opens all four.

How much smaller will my .tb2 be compared to the .tar?

It depends entirely on what's inside. Highly compressible content — source code, JSON/XML/CSV, log files, uncompressed text documents — typically shrinks to 20-30% of the original TAR size (a 4-5x reduction). Already-compressed payloads like JPEGs, MP4 videos, MP3 audio, or ZIP/7Z files inside the TAR will barely shrink at all, because bzip2 cannot meaningfully re-compress data that's already entropy-coded. Expect a few percent savings at best in that case.

TB2 or TGZ — which should I pick?

TB2 (bzip2) produces smaller files; TGZ (gzip) is much faster to both compress and decompress. Pick TB2 when the archive will be downloaded many times and storage/bandwidth matter more than CPU (release tarballs, nightly backups, cold archives). Pick TGZ when you'll be repeatedly creating and extracting archives in a build pipeline, or when consumers might be on slow CPUs. For most modern workloads with cheap CPU and expensive bandwidth, TB2 wins. For ratios approaching xz/lzma without the speed penalty, look at xz itself — bzip2 sits between gzip and xz on both axes.

Why is bzip2 slower than gzip?

Bzip2 runs a Burrows-Wheeler transform followed by move-to-front and Huffman coding on each 900 kB block, which is computationally heavier than gzip's DEFLATE (LZ77 plus Huffman). The BWT step in particular requires sorting block-sized buffers, which scales worse than gzip's sliding-window approach. Decompression is closer in speed — bzip2 decompression is only modestly slower than gzip — but compression can be several times slower in wall-clock terms.

Will my UNIX file permissions and symlinks survive the round-trip?

Yes. TAR stores POSIX permissions, ownership (UID/GID), symbolic links, hard links, and modification timestamps in its header records, and the bzip2 layer is a pure byte-stream compressor that doesn't touch that metadata. When you extract the .tb2 on a UNIX-like system with tar -xjf, permissions and links are restored faithfully. (Note: ownership restoration usually requires extracting as root, otherwise UIDs map to the extracting user.)

Can Windows open a .tb2 file natively?

Not out of the box on older Windows. Windows 10 (build 17063+) and Windows 11 ship a built-in tar command that handles bzip2-compressed TARs from the command line. Windows 11 24H2 added native bzip2/tar/7z extraction in File Explorer. For everything else — older Windows, GUI workflows, batch operations — install 7-Zip, PeaZip, or WinRAR, all of which handle .tb2/.tar.bz2 transparently.

Are there any size limits on the converter?

The web tool handles typical archives without issue. Very large multi-gigabyte TARs may run into upload time and browser memory ceilings. If you're routinely compressing tens of gigabytes, run tar -cjf out.tb2 directory/ locally — that's what the format was built for.

What's the difference between Single Archive and Individual Archives?

Single Archive (the default) extracts the contents of every uploaded .tar and merges them into one combined .tb2. Individual Archives processes each input TAR separately and emits one .tb2 per input. Pick Single Archive when you want a single distributable bundle; pick Individual Archives when you're batch-compressing several unrelated TARs in one go. For other format pairs, see TAR to TGZ, TAR to 7Z, or TAR to ZIP.