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Comprehensive algorithm support

  • Jacksum supports 471 algorithms including ...
  • National and international standards of cryptographic hash functions: SHA-1, SHA-[224,256,384,512], SHA-512/[224,256] (USA, NIST FIPS 180-4); SHA3-[224,256,384,512], SHAKE[128,256] (USA (NIST FIPS 202); GOST, GOST Crypto-Pro (Russia, GOST R 34.11-94); Streebog-[256,512] (Russia, GOST R 34.11-2012); SM3 (China); Kupyna[256,384,512] (Ukraine, DSTU 7564:2014); LSH-256-[224,256], LSH-512-[224,256,384,512] (South Korea, KS X 3262); HAS-160 (KISA, South Korea)
  • All 5 candidates from round 3 the NIST SHA-3 competition (2007-2012): BLAKE-[224,256,348,512], Groestl-[224,256,384,512], JH[224,256,284,512], Keccak[224,256,384,512], Skein-256-[8..256], Skein-512-[8..512], Skein-1024-[8..1024]
  • 3 candidates from round 2 of the NIST SHA-3 competition (2007-2012): ECHO-[224,256,348,512], Fugue-[224,256,348,512], Luffa-[224,256,348,512]
  • Proposals from the 2005 NIST workshops before the SHA-3 competition: DHA-256, FORK-256, VSH-1024
  • International accepted, modern strong cryptographic hash functions: BLAKE2s-[8..256], BLAKE2b-[8..512], BLAKE3, ed2k, HAVAL-[160,192,224,256]-[3,4,5], RadioGatun[32,64], RIPEMD[160,256,320], Tiger2, Whirlpool
  • eXtendable Output Functions (XOF) as cryptographic hash functions with a fixed length: SHAKE128, SHAKE256, KangarooTwelve, MarsupilamiFourteen
  • Broken cryptographic hash functions for education and backwards compatibility purposes: HAVAL-128-[3,4,5], MD2, MD4, MD5, MDC2, PANAMA, RIPEMD-128, SHA-0, SHA-1, Tiger, Tiger/128, Tiger/160, Whirpool-0, Whirlpool-T
  • Checksums that can be found in software products and operating systems: Adler-32, cksum (Minix), cksum (Unix), ELF (Unix), Fletcher's Checksum, FNV-0_[32,64,128,256,512,1024], FNV-1_[32,64,128,256,512,1024], FNV-1a_[32,64,128,256,512,1024], joaat, sum (BSD Unix), sum (Minix), sum (System V Unix), sum [8,16,24,32,40,48,56], xor8, XXH32
  • CRCs that are being used in many software products and protocols: CRC-8 (FLAC), CRC-16 (LHA/ARC), CRC-16 (Minix), FCS-16, CRC-24 (OpenPGP), CRC-32 (FCS-32), CRC-32 (MPEG-2), CRC-32 (bzip2), CRC-32 (FDDI), CRC-32 (UBICRC32), CRC-32 (PHP's crc32), CRC-64 (ISO 3309), CRC-64 (ECMA-182), CRC-64 (prog lang GO, const ISO), CRC-64 (.xz and prog lang GO, const ECMA)
Multi-core/multi-CPU support
  • Supports multi-threading on multi-processor and multi-core computer systems
  • Calculates multiple hashes simultaneously, files are read only once, and the calculation load is distributed on the available cores
  • Processes multiple files simultaneously, i.e. files are read in parallel

Algorithm selection

  • Select one, a few, many, or all algorithms for hash calculation and verification
  • Select algorithms manually, filter them by name or message digest bit width
  • Select any of the predefined CRCs
  • Customize your own CRC, because Jacksum supports the standard "Rocksoft (tm) Model CRC Algorithm", and an extended model of it
  • Algorithms can be concatenated in order to calculate many algorithms in one pass

Input related features

  • Recursively directory traversal
    • Processes directories recursively, and allows to limit the depth
    • Detects file system cycles and it avoids endless loops
    • Allows you to control how symbolic links on files and/or directories should be handled on all operating systems
  • Input from almost any source
    • Calculates hashes from files, stdin, file lists, command line argument values on all operating systems: Windows, Linux, Unix (e.g. macOS, BSD)
    • Calculates hashes from disks, and partitions on all operating systems: Windows, Linux, Unix (e.g. macOS, BSD)
    • Calculates hashes from block devices, character devices, named pipes, sockets, and sparse files on all Unix-like operating systems
    • Calculates hashes from NTFS Alternate Data Streams (ADS) on Microsoft Windows
    • Calculates hashes from doors on Solaris
  • Character sets, Unicode and BOM support
    • Full Unicode file name support for input files
    • Allows you to specify the character set for input files: GB18030, UTF-8, UTF-16, UTF-16BE, UTF-16LE, UTF-32, UTF-32BE, UTF-32LE, etc.
    • Ignores an optional Byte-Order-Mark (BOM) from the input if a BOM is allowed, but not required by the selected charset
  • The sky is the limit
    • Handles allowed max. length of filenames properly (e.g. 255 max. characters for a filename on Microsoft Windows NTFS file systems)
    • Handles allowed max. length of paths properly (e.g. 32,767 max. characters for the entire path on Microsoft Windows NTFS file systems)
    • It is large file aware, it can process file sizes up to 8 Exbibytes (= 8,000,000,000 Gibibytes), presupposed your operating system respectively your file system is large file aware, too.

Output related features

  • predefined standard formats
    • Output can occur in predefined standard formats (BSD-, GNU/Linux-, openssl-, and Solaris style, SFV or FCIV)
  • user defined formats
    • Use comprehensive format options to get the output you need
    • Create your own format and define a compatibility file to be able to read your own format again
    • create ed2k-links, magnet-links, Solaris' pkgmap format
    • Specify one of the supported encodings for representing hash values: Hex (lower- and uppercase), Base16, Base32 (with and without padding), Base32hex (with and without padding), Base64, Base64url, BubbleBabble, and z-base-32.
  • character sets, Unicode, and BOM support
    • Full Unicode file name support for output files
    • Allows you to specify the character set for output files: GB18030, UTF-8, UTF-16, UTF-16BE, UTF-16LE, UTF-32, UTF-32BE, UTF-32LE, etc.
    • Adds an optional Byte-Order-Mark (BOM) to the output if a BOM is allowed, but not required by the selected charset

Integrity verification features

  • Check against a pre-calculated hash set, and detect ok, failed, missing, and new files
  • Optionally include not only the hash, but also the file size and/or file modification timestamp of files for performing integrity checks
  • Use predefined compatibility files to read and write popular 3rd party format styles (GNU/Linux, BSD, SFV, FCIV, openssl, etc.)
  • Create and use your own compatibility files

Find objects with Jacksum

  • Find the algorithm that was used to calculate a checksum/CRC/hash
  • Find all files that match a given hash value (find duplicates of a file)
Cross-platform support
  • Operating Systems
    • Microsoft Windows (e.g. Microsoft Windows 10, and 11)
    • GNU/Linux (e.g. Ubuntu)
    • Unix (e.g. BSD-flavors, macOS, Solaris)
    • any other operating system or architecture with an OpenJDK compatible Java Runtime Environment (JRE) or Java Development Kit (JDK)
  • Supported architectures are dependent on the JDK
    • x86 64 bit (x64)
    • x86 32 bit (x86)
    • ARM 64 bit (AArch64, resp. M1)
    • ARM 32 bit (AArch32)
    • PPC 64 bit (ppc64)
  • written entirely in Java
    • no recompilation required
Interaction with other tools
  • Works with the SendTo-feature on many file browsers (e. g. macOS Finder, Microsoft Windows Explorer, Gnome Nautilus, KDE Konqueror, ROX Filer, etc.)
  • As it has a command line interface, Jacksum can be used in cronjobs and autostart environments
  • Jacksum returns an exit status which is dependent on the result of the calculation/verification process, so you can use Jacksum in scripts and batches and control the code flow in your own scripts
  • Use predefined compatibility files to read and write popular 3rd party format styles in order to interact with other tools (GNU/Linux, BSD, SFV, FCIV, openssl, etc.)


  • The program is mature and very stable
  • Specify your preferred level of verbosity
  • Obtain details for each algorithm, including comprehensive compatibility lists
Developer support
  • Entire source code has been opened, is hosted on GitHub, and accessible using git
  • The project has been mavenized with a pom.xml which makes it easy to work in your preferred IDE
  • Jacksum provides an API, so you can incorporate Jacksum in your own projects
  • Javadoc is available
  • Jacksum keeps compatibility with JDK 11, but takes all the advantages of  JDK 11+ if available



Das Team

Die Liste von Mitwirkenden finden Sie stets im neuesten Download und in der Copyright Sektion. Der Gründer und Leiter dieses Projektes ist Johann N. Löfflmann aus Deutschland. Seit 2002 arbeitet er in seiner Freizeit mit talentierten Menschen aus aller Welt zusammen, um Jacksum gemeinsam weiter zu verbessern.

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