Credit Card Validator

Check a card number's Luhn checksum and identify its network, entirely in your browser

This only checks whether the number is mathematically well-formed (passes the Luhn checksum), it does NOT verify the card is real, active, or has funds. No card data is sent anywhere; this all runs in your browser.

Card number

Spaces and dashes are stripped automatically before checking.

About this tool

Card numbers include a built-in checksum digit, computed with the Luhn algorithm, whose only job is catching typos, not confirming a real account. This tool strips spaces and dashes from what you type, runs the real Luhn check, and matches the number's prefix and length against known network patterns (Visa, Mastercard, American Express, Discover, JCB, UnionPay).

How to use it:

Does passing Luhn mean the card is real?

No. Luhn only confirms the number is internally consistent, it says nothing about whether the card was ever issued, is active, or has any funds. Only the card network or issuing bank can confirm that.

What does "Unknown network" mean?

The number passed Luhn but its prefix and length didn't match any of the known network patterns this tool checks, it may belong to a less common network, or simply be a made-up but Luhn-valid number.

Is it safe to type a real card number here?

Nothing you type is ever sent over the network, there is no fetch call anywhere in this tool's code, and everything runs locally in your browser tab. That said, it's good practice to avoid pasting sensitive real numbers into any web page you don't need to.

Which networks are detected?

Visa, Mastercard, American Express, Discover, JCB, and UnionPay, based on published prefix and length rules for each.