Runs locally in your browser. Nothing you enter is uploaded to our servers.
Result will appear here
Tips for Luhn checks
Luhn validates checksums — it does not prove a card is issued or funded.
Do not store full PANs unless you must and are PCI-compliant.
Use only test card numbers in non-production systems.
Mask displayed numbers except last 4 when showing to users.
A failed Luhn check means fix input before charging attempts.
Luhn checksum for card-shaped numbers
Processing stays in your browser — your input is not uploaded to our servers.
Luhn is the digit check used on many card PANs and some IDs. Passing Luhn means the number is well-formed, not that a card exists or has funds.
Never paste live customer PANs into a browser tool on a shared machine. Prefer test BINs from your acquirer.
Run a Luhn check
Paste digits only
Spaces and dashes are usually stripped; letters will fail.
Check the checksum
A fail is a typo. A pass is still not an authorization.
Clear the input
PAN is PCI-sensitive. Do not leave it in history or screenshots.
Luhn validator FAQ
Does this charge a card?
No. There is no payment gateway. Luhn is a checksum only.
Is the number sent to a bank?
No. The algorithm runs in the browser.
Why use this in QA?
To catch mistyped test PANs before they hit a sandbox that also rejects bad Luhn.