File Hash Checker (MD5, SHA-256 Checksum)

Publishers list an MD5, SHA-1 or SHA-256 checksum next to downloads so you can confirm the file arrived intact and unaltered. This checker hashes one or many files directly in your browser — they are read in pieces, so large ISO images work too — and compares the result with the hash you paste, or with a whole SHA256SUMS or md5sum list matched by file name. Nothing is uploaded.

How to use this tool

1. Choose or drop the files to check.
2. Paste the expected hash or the checksum list from the download page (optional).
3. Tick the algorithms you want; one needed for the pasted hash is added automatically.
4. Read Match or MISMATCH, or copy the checksum list for your own records.

Formula

The expected algorithm is recognised from the hash length in hex digits: 8 = CRC-32, 32 = MD5, 40 = SHA-1, 64 = SHA-256, 96 = SHA-384, 128 = SHA-512.

Comparison ignores upper/lower case, spaces and colons. Base64 hashes and SRI values such as sha256-… are converted to hex first. In a list, lines in the GNU format "hash filename" (or "hash *filename") and the BSD format "SHA256 (filename) = hash" are matched to your files by name.

Example

The 26-byte text file "Hello world.\nSecond line.\n" has the SHA-256 acb39f9c…83a8daff and the MD5 76ab5293…9d132edbfc. Pasting the SHA-256 in upper case with spaces still gives Match (SHA-256); an MD5 that differs in the last digit gives MISMATCH.