TAR.GZ to TB2 Converter

How to Convert TAR.GZ to TB2 Online

1. Upload Your TAR.GZ File: Drag and drop the archive or click "+ Add Files" to select one or more .tar.gz / .tgz files from your computer. Batch uploads are supported.
2. Pick the TB2 Output: The output extension is locked to TB2 (a shorthand for .tar.bz2 — the same TAR + bzip2 container, just a shorter filename). The bzip2 compression layer replaces the gzip layer inside the archive.
3. Choose Combine Mode (Optional): Under "Combine?" pick Single Archive to merge multiple uploads into one .tb2 bundle, or Individual Archives to produce one .tb2 per source file. For converting a single .tar.gz, the default already produces one .tb2.
4. Convert and Download: Click Convert. The server extracts the gzip layer, re-wraps the TAR payload with bzip2, and hands back a .tb2 file — no sign-up, no watermark, no install.

Why Convert TAR.GZ to TB2?

.tar.gz (TAR + gzip, file extension .tgz for the short form) and .tb2 (TAR + bzip2, also written .tar.bz2 or .tbz2) are both Unix-style archive bundles. The TAR layer is identical; only the compression algorithm wrapped around it differs. Gzip uses the DEFLATE algorithm (released 1992) and is fast. Bzip2 uses the Burrows-Wheeler transform with Huffman coding (released 1997) and typically produces files 10-20% smaller on text-heavy payloads — source trees, log bundles, JSON dumps — at the cost of 2-4x slower compression and up to 6x slower decompression.

• Shrink source-code tarballs for distribution — Bzip2's larger block size (up to 900 KB, vs gzip's 32 KB sliding window) finds longer-range patterns in repeated text. A 50 MB .tar.gz of a Linux kernel source tree often drops to 40-43 MB as .tb2.
• Match the format your build system expects — Many older configure / make workflows, Gentoo Portage trees, Slackware packages, and pkgsrc recipes ship sources as .tar.bz2 / .tb2. Re-pack a vendor's .tar.gz to match the format the rest of your pipeline ingests.
• Smaller backups for cold-storage uploads — When uploading a server backup to S3 Glacier or Backblaze B2, paying for the bzip2 CPU time once saves 10-20% on storage forever. The slow decompression is fine because you rarely restore.
• Fit a CI artifact under a tighter size cap — GitHub Actions caches default to a 10 GB repo limit; nudging individual artifacts smaller with bzip2 leaves headroom for other jobs.
• Match upstream conventions when forking — Many GNU projects (bash, coreutils, gcc, binutils) publish source tarballs in .tar.gz, .tar.bz2, and .tar.xz simultaneously. If your downstream tooling parses only one, convert once on intake.
• Shorter filename than .tar.bz2 — .tb2 is the same archive but with one extension instead of a double extension. Helpful on filesystems or CMS upload forms that mis-handle dotted suffixes.

TAR.GZ vs TB2 (TAR.BZ2) — Format Comparison

Compression Profile Quick Guide

Frequently Asked Questions

Is .tb2 the same as .tar.bz2?

Yes — .tb2, .tbz2, .tbz, and .tar.bz2 all refer to the same container: a TAR archive compressed with bzip2. The single-extension forms (.tb2, .tbz2) exist because some legacy filesystems and download managers handled double extensions poorly. tar itself reads all of them with tar -xjf (or tar -xf on modern GNU tar, which auto-detects).

How much smaller will my .tb2 be than the original .tar.gz?

For text-heavy payloads (source code, logs, JSON, XML) expect roughly 10-20% smaller. For already-compressed payloads inside the archive (JPEG, PNG, MP4, MP3, ZIP-of-ZIPs, pre-compressed binaries), the savings collapse to ~1-3% because both gzip and bzip2 struggle on entropy-dense data. If most of your archive is media files, the conversion mostly costs CPU without buying you space.

Will I lose any files or metadata during the conversion?

No. The TAR layer carries the file tree, permissions, ownership, mtimes, symlinks, and (on most tar implementations) extended attributes; the conversion only swaps the outer compression wrapper. The .tb2 you download extracts byte-identical to the original .tar.gz payload — tar -tvf on either will list the same entries with the same metadata.

Why is bzip2 so much slower than gzip?

Bzip2 runs the input through a Burrows-Wheeler transform (which sorts permutations of large blocks), a move-to-front transform, run-length encoding, and Huffman coding — several heavyweight passes per 100-900 KB block. Gzip's DEFLATE uses one lightweight LZ77 + Huffman pass over a 32 KB window. The extra work is what buys the better ratio, but the cost compounds on multi-GB archives.

Can I convert a .tar.gz to .tb2 from the command line instead?

Yes — gzip -dc archive.tar.gz | bzip2 -9 > archive.tb2 streams it without writing the intermediate .tar to disk. The xconvert flow exists because (a) you don't always have bzip2 installed (Windows lacks it by default), (b) browser drag-and-drop is faster than shelling out for a one-off, and (c) batch mode handles many files in a single session.

Do GitHub Releases, Sourceforge, or PyPI accept .tb2?

GitHub Releases, Sourceforge file releases, and most distro package mirrors accept arbitrary filenames — .tb2, .tbz2, and .tar.bz2 all work. PyPI source distributions (sdist) historically accepted .tar.bz2 but since the move to PEP 517 / build backends, .tar.gz is the standard and .tb2 may be rejected by twine upload; check your packaging tool's accepted formats before uploading.

My archive contains binaries — should I still convert?

Probably not. Binaries (compiled .so / .dll / .exe, stripped ELF, AOT-compiled .pyc) compress poorly with both algorithms because they're already entropy-dense. You'll spend CPU for a 1-3% savings. Bzip2 shines on natural-language and source-code inputs; for binary blobs, leaving the file as .tar.gz or moving to .tar.xz (LZMA2, which handles binaries better than bzip2) is usually wiser.

What about .tar.xz — should I use that instead?

For new archives where storage size matters more than decompression speed, .tar.xz typically beats both .tar.gz and .tb2 on ratio (often by another 10-30%) and decompresses faster than bzip2. Most modern Linux distros default to .tar.xz for source distribution. If your downstream tooling supports it, convert to .tar.xz instead — try TAR.GZ to TAR.XZ. If you need bzip2 specifically for compatibility with an older build system, stick with .tb2.

Can I go the other direction — .tb2 back to .tar.gz?

Yes. The conversion is lossless either way because the TAR payload is unchanged. Use TAR.BZ2 to TAR.GZ or unpack first with TAR.GZ to TAR and re-wrap manually. For other targets see TAR.GZ to 7Z or TAR.GZ to ZIP.