rarpar

rarpar is a command-line tool for RAR archives and PAR2/PAR3 recovery sets, written in Rust. Point it at an archive, a recovery file, or a messy download folder, and it works out what is there, repairs what it can, rebuilds missing volumes, and extracts with every byte checked.

It is built on library crates in this repository that are published on crates.io. The CLI itself ships as release binaries and source, not on crates.io.

rarpar is not an official RAR, PAR2 or PAR3 tool. It ships no binaries named unrar, rar, par2 or par2repair, and it cannot create RAR archives or change their members: the one change it makes to an existing RAR5 archive is adding or removing the PAR3 service record of par3 inside.

What it does

• Finds RAR, REV, PAR2 and PAR3 sets in a file or folder.
• Verifies and repairs PAR2 and PAR3 sets before extracting.
• Creates PAR2 sets (par create) and PAR3 sets (par3 create).
• Rebuilds missing RAR volumes from .rev files.
• Embeds PAR3 recovery inside RAR5 archives and repairs them from it (par3 inside, experimental).
• Extracts RAR archives, including encrypted ones, with integrity checks on.
• Compresses, decompresses, tests and lists .xz files on several threads.
• Can delete the source files after a successful extraction, to the trash by default.
• Reports in JSON for scripts.
• Accepts UnRAR's command shape, including -vp for archives still downloading.

Speed

How many times faster than the reference tools a whole rarpar run is (2.0× is half the time). The references are RARLAB's UnRAR and par2cmdline-turbo 1.5.0.

CPU	Arch	Instruction set	unrar (binary)	unrar (text)	par2 (heavy)
AMD EPYC 9R14 (Zen 4)	x86-64	GFNI + AVX-512	2.2×	1.6×	3.1×
Intel Xeon Platinum 8488C (Sapphire Rapids)	x86-64	GFNI + AVX-512	2.3×	1.5×	2.5×
Intel Core i5-1240P (Alder Lake)	x86-64	GFNI + AVX2	2.2×	1.4×	2.7×
Intel Xeon Platinum 8124M (Skylake-SP)	x86-64	AVX-512	1.8×	1.3×	2.2×
AMD Ryzen 5 3600 (Zen 2)	x86-64	AVX2	2.2×	1.7×	1.9×
Intel Xeon E5-2666 v3 (Haswell)	x86-64	AVX2	1.8×	1.3×	2.2×
Intel Atom C3538 (Denverton)	x86-64	SSSE3 (no AVX)	1.8×	1.4×	1.5×
Apple M5 Max †	arm64	NEON	1.3×	1.5×	7.8×
Arm Cortex-A72	arm64	NEON	2.3×	1.5×	1.4×
Arm Neoverse N1	arm64	NEON	2.9×	1.6×	1.8×
Arm Neoverse V2	arm64	NEON	3.1×	1.7×	1.9×

• unrar (binary) is extracting stored media, with and without encryption.
• unrar (text) is extracting compressed data, including PPMd.
• par2 (heavy) is the two heavy repairs.
• † From an older release (rarpar 0.3.3, against par2cmdline-turbo 1.4.0), awaiting a re-measure. The other rows measure rarpar 0.9.0 and 0.9.1.
• The Apple PAR2 figure is against par2cmdline-turbo's macOS arm64 build, which is much slower than its Linux and Windows builds.

Encrypted extraction gains the most, up to 12.7×. A few cases are at or just below parity, among them PAR2 verify and missing-volume repair on the cloud x86-64 machines and dense source text on Alder Lake and Denverton.

PAR3, against par3cmdline 0.0.1 on Alder Lake, Zen 2 and Denverton: creating is 4.4×–7.1× faster, verifying 5.2×–6.0×, repairing 6.2×–10×.

Release builds run on the CPU only; the GPU options of the PAR2 library are not turned on. Every case, chart, method and version is in docs/benchmark.md.

Install

With Homebrew:

brew install scryer-media/rarpar/rarpar

Or download the archive for your platform from GitHub Releases and put rarpar on your PATH. Archives include a manpage and shell completions under share/, signed checksums and build provenance; Linux comes in GNU and musl builds. Release verification shows how to check them.

From source:

cargo install --locked --path tools/rarpar

Quick start

Do everything for a download (rarpar auto is the same):

rarpar ~/Downloads/some-release

See what it would do, without changing anything:

rarpar inspect --json ~/Downloads/some-release

Extract somewhere else, then move the sources to the trash:

rarpar auto --output ~/Extracted --delete-sources ~/Downloads/some-release

--permanent-delete deletes instead of using the trash, and rarpar cleanup --dry-run shows what cleanup would remove.

Commands

rarpar rar list archive.part1.rar
rarpar rar extract archive.part1.rar ./out
rarpar rar restore-volumes archive.part1.rar archive.part1.rev
rarpar rar test-volumes archive.part1.rev archive.part2.rev

rarpar par verify release.par2
rarpar par repair release.par2
rarpar par create ./release/release --recovery-percent 5 part01.rar part02.rar

rarpar par3 create release.par3 part01.rar part02.rar -s 1048576 -r 5
rarpar par3 verify release.par3
rarpar par3 repair release.par3

rarpar xz compress data.tar
rarpar xz decompress data.tar.xz ./out
tar -c ./release | rarpar xz compress > release.tar.xz

rarpar rar restore-volumes --dry-run reads every volume of the set, names the volumes a restore would rebuild and counts the usable .rev files that cover them. Where the restore would fail, for too few usable .rev files or a file already in its way, the dry run fails the same way. It writes nothing.

Pipes work without temporary files: par verify --name checks a file as it streams in, par3 create - and xz compress --sidecar make a recovery set from a stream, and xz reads and writes standard input and output.

The command reference covers every command, including PAR3 options, recovery sets written alongside an archive, file placement, and folder scanning limits.

Passwords

rarpar --password-file passwords.txt ./release
rarpar --password-env RAR_PASSWORD ./release
rarpar --password-fd 3 ./release 3< passwords.txt

Files and descriptors hold one password per line. If none works and you are at a terminal, rarpar asks, with the input hidden. Passwords are never printed or written to JSON.

Cleanup

Cleanup only removes files it used: the RAR volumes, their .rev files, and the PAR2 and PAR3 files for that set. It leaves .nfo, .sfv, samples, subtitles and anything else alone.

UnRAR-compatible mode

Programs that expect UnRAR can call rarpar the same way:

rarpar x archive.part1.rar /dest/
rarpar t archive.rar
rarpar l archive.rar

x, e, t, l and lb work, with the common switches. -vp waits for each volume while a set is still downloading. See docs/rarpar-compatibility.md.

Crates

• unrar-rs: reads and extracts RAR archives.
• par2-rs: creates, verifies and repairs PAR2 sets.
• par3-rs: creates, verifies and repairs PAR3 sets.
• reedsolomon-rs: the recovery math they share.
• tools/rarpar: this command.

Development

Test files live in a separate signed store, not in Git (docs/test-corpus.md). After cloning:

git config core.hooksPath .githooks
cargo run --locked -p xtask -- test-corpus hydrate --profile unrar --profile par2

The checks CI runs:

cargo fmt --check --all
cargo clippy --locked --workspace --all-targets --features unrar-rs/unstable-internals -- -D warnings
cargo nextest run --locked --workspace --lib --bins --examples --no-fail-fast --features unrar-rs/unstable-internals

More in docs/: publishing, packaging, fuzzing, and the technology radar. Changes by version are in CHANGELOG.md.

License

• rarpar is GPL-3.0-or-later, with a section 7 permission to combine it with unrar-rs (tools/rarpar/LICENSE). It includes unrar-rs by default, so an ordinary build, cargo install or release archive carries the UnRAR restriction too. Release archives include one LICENSE file with the full terms.
• unrar-rs is Apache-2.0 plus the UnRAR licence restriction, from 0.11.0 on. Its RAR engine was developed from RARLAB's UnRAR source, and the restriction still governs that code (LICENSE).
• par2-rs (from 0.10.11), par3-rs (from 0.5.1) and reedsolomon-rs (from 0.4.10) are Apache-2.0. The par2-rs tests adapted from par2cmdline's GPL-2.0-or-later suite stay GPL-3.0-or-later and are not published with the crate. reedsolomon-rs includes GF(2¹⁶) kernels ported from ParPar, which its author released as public domain or CC0.

Earlier releases of the library crates stay under GPL-3.0-or-later (unrar-rs with the UnRAR restriction).

The UnRAR restriction covers unrar-rs and rarpar only, never the PAR2, PAR3 or Reed-Solomon crates. That is why those are published with an SPDX licence expression, while unrar-rs and rarpar use a licence file: the restriction has no SPDX form.

Papers and borrowed algorithms are credited in ATTRIBUTION.md.