RapidCRC Unicode

RapidCRC is an open source CRC/MD5/SHA hashing program. I've extended the current unicode support to allow writing of unicode .sfv/.md5/.sha1/.sha256/.sha512 files, which can be turned on/off through the settings page. Unicode sfv files are written as UTF-16LE with BOM or UTF-8 (with or without BOM), and RCRC now performs a codepage detection. I've also expanded the shell extension that was included in the sourcecode to enable all operations directly from the extension.

List of other new features:

  • multithreaded hash calculations with asynchronous I/O
  • ed2k hash calculation
  • SHA hash calculation
  • job queueing
  • popup menu to copy the calculated hashes to the clipboard

RapidCRC is released under the GPL - the sourcecode with my modifications can be found below. Be warned however that my documentation in the sourcecode is not as good as the original RapidCRC source.

LM from www.portablefreeware.com made a nice introductory video about RapidCRC:
YouTube Link



posted on 10/11/2022 - 23:38
  • b3sum compatibility
  • Added option to close after shell extension filename/stream actions
  • Added option to add other hash types to a ntfs stream
  • Reduced memory usage with many files


posted on 08/20/2021 - 22:04
  • Added option for unbuffered reads
  • Default to utf8 for opening
  • Natural sorting for filenames


posted on 03/29/2021 - 23:32
  • BLAKE3 in shell extension
  • New context menu entry to calculate hashes
  • Moved "Copy to Clipboard" to submenu


posted on 02/25/2021 - 22:21
  • BLAKE3 support
  • New option to force-open as regular file (for hash files)
  • New menu entrties to select/deselect all
  • Del/Ctrl+A hotkeys in list
  • Timezone information in file comments


posted on 12/24/2020 - 15:25
  • Hidden files can now be overwritten when saving hash files
  • Saving hash in NTFS stream will now keep the modified date
  • New option to always open a new program window from explorer


posted on 04/25/2020 - 17:52
  • Copy to Clipboard was not working for Blake2sp


posted on 04/18/2020 - 21:02
  • Fixed a problem with configuring the shell extension menu
  • Added a win2k compatible portable download - this will probably not happen every release


posted on 02/02/2020 - 20:45
  • Updated sha3 algorithms
  • Compiled with Visual Studio 2017. This removes win2k compatibility, but improves sha3 performance by 300%. If anyone is still using the win2k version let me know and I'll put up another build.

Update: there was a problem with the 32bit version, 0.3.31 should fix that.


posted on 11/16/2019 - 14:04
  • Fixed memory leak in shell extension when used on win2k/winxp
  • Register blake2sp file extension
  • Fixed column width for blake2sp
  • Fixed click-mapping in the context menu config dialog


posted on 07/02/2019 - 20:42
  • Added support for Blake2sp
  • Fixed an installer issue with the shell extension
  • Grouped some buttons


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