Validating that a test card number you've copied is well-formed (test cards from Stripe's docs or similar all pass Luhn). Sanity-checking input fields in a form — does the number satisfy the basic structure before round-tripping to a payments API that'd otherwise charge for the lookup? Auditing a card number that "looks wrong" to see whether it's a typo (Luhn fails) or a brand mismatch (length wrong for the prefix).

"Structurally valid" doesn't mean "issued" or "active". Real validation requires a payment processor — which costs money or places a hold. This tool catches typos, not closed accounts. Don't paste real card numbers anywhere — including this tool. The browser doesn't transmit them, but a screen-recorder, browser extension, or open dev-tools panel can. Use a known test number instead. Some 16-digit numbers aren't cards. Loyalty cards, gift cards, and some prepaid SKUs reuse the format; Luhn pass + brand match doesn't guarantee a payment instrument. Co-branded cards. Cards issued under one brand may show another's logo. The brand detection here uses the canonical issuer prefix, not the printed logo.

Validador de Tarjeta de Crédito

Valida un número de tarjeta con Luhn y detecta la marca. Funciona localmente — el número nunca se envía.

Card number

Spaces and hyphens are ignored. Number is never sent — validation is entirely in your browser.

Resultado

Introduce un valor arriba para ver el resultado.

What is this for?

Card numbers carry a built-in checksum (the Luhn / mod-10 algorithm) and start with prefixes that identify the issuing brand. Together those let you catch typos and identify the brand before sending a number to a payment processor. This tool runs both checks 100% in your browser — the number you paste never leaves the page. It's developer-grade structural validation, not a fraud-check or live-card lookup.

When to use it

Validating that a test card number you've copied is well-formed (test cards from Stripe's docs or similar all pass Luhn).
Sanity-checking input fields in a form — does the number satisfy the basic structure before round-tripping to a payments API that'd otherwise charge for the lookup?
Auditing a card number that "looks wrong" to see whether it's a typo (Luhn fails) or a brand mismatch (length wrong for the prefix).

Common gotchas

"Structurally valid" doesn't mean "issued" or "active". Real validation requires a payment processor — which costs money or places a hold. This tool catches typos, not closed accounts.
Don't paste real card numbers anywhere — including this tool. The browser doesn't transmit them, but a screen-recorder, browser extension, or open dev-tools panel can. Use a known test number instead.
Some 16-digit numbers aren't cards. Loyalty cards, gift cards, and some prepaid SKUs reuse the format; Luhn pass + brand match doesn't guarantee a payment instrument.
Co-branded cards. Cards issued under one brand may show another's logo. The brand detection here uses the canonical issuer prefix, not the printed logo.

Test numbers (safe to paste)

Visa 4242 4242 4242 4242 · Mastercard 5555 5555 5555 4444 · Amex 3782 822463 10005 · Discover 6011 1111 1111 1117