Checksum MD5 and SHA1 calculator

Online MD5 and SHA1 checksum calculator will perform calculations right within your browser without uploading files to the server.

MD5:
SHA1:
Length:

Please select file to calculate MD5 and SHA1 checksum

Tests

Testing FileReader
Testing MD5 in browser
Testing SHA1 in browser

Why calculate checksum?

MD5 and SHA1 are used to calculate fingerprint of large amount of data, i.e they map something with a lot of bits to just a few bits (128 in case of MD5 and 160 in case of SHA1).

This is useful because one can compare these small hashes of the downloaded file with the hash provided by trusted source to make, reasonably safe assumption, that downloaded file is the same as original file.

Why calculate checksum using MD5?

MD5 is popular one way hash function developed by R. Rivest in 1991. It is commonly used to verify data integrity of file downloads. While flaws have since been found it is still widely used as to fingerprint files on the web. Supplementing MD5 hash with SHA1 greatly reduced MD5 weaknesses.

Why calculate checksum using SHA1?

SHA1 is designed by NSA and standardized by NIST. While collision attach theoretically exists in SHA1 it has not yet been demonstrated (as of early 2014). SHA1 produces 160 bit fingerprint. It is widely used on the web, althrough less widely than MD5 as a fingerprint for downlaods. Additionally SHA1 is used to ensure integrity in many other systems including GIT.

Calculating MD5 checksum and SHA1 checksum on Microsoft Windows?

On Windows there are few options to calculate MD5 and SHA1 checksums. Microsoft provides File Checksum Integrity Verifier (FCIV) utility.

From microsoft support site you can download File Checksum Integrity Verifier (FCIV) utility Usage is:

C:\>fciv.exe -both myfile.txt
//
// File Checksum Integrity Verifier version 2.05.
//
                MD5                             SHA-1
-------------------------------------------------------------------------
e59ff97941044f85df5297e1c302d260 648a6a6ffffdaa0badb23b8baf90b6168dd16b3a myfile.txt
        

An alternative is to use one of many graphical user interface applications like QuickHash

Calculating MD5 checksum and SHA1 checksum on Apple Macintosh (MacOS X)?

MacOS X comes preinstalled with md5 command, and shasum command.

The usage is:

        # md5sum myfile.txt
        e59ff97941044f85df5297e1c302d260 myfile.txt
        # shasum myfile.txt
        648a6a6ffffdaa0badb23b8baf90b6168dd16b3a myfile.txt
        

Calculating MD5 checksum and SHA1 checksum on Linux, Ubuntu and other Unixes?

Most Linux distributions come with the md5sum and shasum utilities so installation is usually unnecessary.

The usage is:

        # md5sum myfile.txt
        e59ff97941044f85df5297e1c302d260 myfile.txt
        # shasum myfile.txt
        648a6a6ffffdaa0badb23b8baf90b6168dd16b3a myfile.txt
        

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