Canadian · Validation
ISAN number validator.
Check the format and check characters of an International Standard Audiovisual Number (ISAN): 16 hex digits plus a check character, optionally followed by an 8-hex-digit version and a second check character. Leave the check characters off and this shows what they should be. This checks format and checksum only: it cannot confirm an ISAN was issued or which work it identifies. Everything runs in your browser: nothing you type is transmitted anywhere.
Inputs
Result
Enter an ISAN and press Validate.
How the ISAN check characters work
An ISAN identifies an audiovisual work (film, episode, trailer, and so on). Its 16 hexadecimal digits are a 12-digit root and a 4-digit episode, followed by a check character. An optional 8-hex-digit version segment identifies a specific version (dub, cut, format) and is followed by a second check character. In printed form the parts are grouped in fours, for example ISAN 0000-0001-8947-0000-8-0000-0000-D.
Both check characters use the ISO 7064 MOD 37,36 system named in ISO 15706. Start with 36. For each hex digit (values 0 to 15), add it to the running value, subtract 36 if the result is 36 or more, use 36 if the result is 0, then double it and subtract 37 if the result is 37 or more. After the last digit, the check character is 0 if the running value is 1, otherwise 37 minus the running value, written 0-9 then A-Z. The first check character covers the first 16 digits; the second covers all 24 (root, episode and version).
The ISAN User Guide's worked example, B159-D8FA-0124-0000-K, gives a check character of K. python-stdnum's isan.py uses the same algorithm and agrees on 0000-0001-8947-0000-8-0000-0000-D and 0000-0001-8CFA-0000-I-0000-0000-K.
Sources: ISAN User Guide v2.4, Annex A and python-stdnum isan.py.
What a passing checksum does and doesn’t tell you
This tool checks format and checksum only. Valid check characters prove the characters are internally consistent. They cannot confirm the ISAN was ever registered, that it is active, or which work or version it belongs to. To look one up, use the ISAN registry at isan.org. This tool makes no lookup: it runs entirely in your browser, and nothing you type is transmitted, stored, or logged.