Open Source C Hash Calculators

MultiPar is a Windows file recovery utility that creates and processes parity files to protect data against corruption or loss. It uses the Parchive system to generate recovery information for selected files and directories. Users can verify file integrity and repair damaged or missing data when sufficient recovery blocks are available. The application supports PAR2 recovery files alongside checksum verification using SFV and MD5 formats. Additional verification options help locate files that have been moved or renamed. FLAC fingerprint support enables integrity checking for compatible audio collections. Its recovery engine can use multicore processing and compatible GPU acceleration. MultiPar is particularly useful for protecting archives, backups, and large file collections.

HashCheck is a free, open-source Windows shell extension that calculates and verifies file checksums directly from File Explorer. It adds a Checksums tab to file properties, making hash values accessible without separate command-line tools. Users can generate checksum files for individual files, multiple selections, or entire directories. The application verifies downloaded files against existing checksum records to detect corruption or unintended changes. Supported algorithms include CRC32, MD4, MD5, SHA-1, SHA-2, and SHA-3 variants. Multithreaded processing improves performance when calculating checksums for large collections. HashCheck supports SFV and other common checksum file formats. Its lightweight architecture provides multilingual interfaces and native Windows Explorer integration.

An open source files hash calculator for Windows and macOS. * MD5, SHA1, SHA256 and SHA512. * Drag & drop. * Integrated with context menu in Explorer/Finder. * Support Windows 7 and later. * Support macOS 13 and later, with universal binary. * Support Dark Mode. * English and Simplified Chinese UI. The icon "希" is from hash in Chinese "哈希".

ReHash is an easy-to-use console-based hash calculation tool written in C++. It supports many algorithms and output formats and it can be fully configured using some of the many command-line arguments which can be passed to the tool.