Credit Card Validator — Luhn Check, Brand Detection & Formatting

Paste any number to verify the Luhn checksum, identify the brand from the BIN prefix and see it grouped the way payment forms display it — built for QA and developers.

Quick answer: Free credit card validator: check if a card number is structurally valid (Luhn algorithm), detect the brand, and format it correctly — for testing payment forms. No real cards needed.

Card number to validate (digits, spaces & dashes ok)

–Luhn checksum

–Brand

–Length check

🔒 Structural check only — this tool can never know if a card is active, and you should never paste a real card number into any website.

How to use

Paste a number — spaces and dashes are fine; only digits matter.
Read the verdict — Luhn valid/invalid, detected brand, expected length.
Test your forms — use published sandbox test numbers (e.g. Stripe's 4242…) with this checker during development.

About this tool

Payment forms run three checks before ever contacting a bank: length, prefix (BIN/IIN) and the Luhn checksum. This validator runs exactly those: it confirms the number is structurally sound, names the brand (Visa 4…, Mastercard 51–55/2221–2720, Amex 34/37, Discover 6011/65, JCB, UnionPay, Diners), and reformats it in the brand's display grouping. Use it to test your own checkout forms with sandbox numbers — never enter real card numbers here or anywhere you do not fully trust (there is no reason to: no validation happens on your device).

FAQ

Does this check if a card actually works or has money?

No — and no honest tool can. Luhn validation only proves a number is structurally possible; activation and balance checks happen at banks.

Is it safe to paste my real card?

Don't paste real card numbers into ANY website you don't need to. For form testing use published sandbox numbers from your payment provider's docs.

Which brands are detected?

Visa, Mastercard, American Express, Discover, JCB, Diners Club and UnionPay, plus expected lengths per brand.

Rate this tool

Your rating stays in this browser (local storage) — nothing is sent to any server.

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The complete credit card validator guide

Prefer the long version — a worked example, the mistakes people actually make, and answers to real questions? The blog guide Credit Card Validator — Complete Guide, Mistakes & FAQ covers all of it step by step.

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Credit Card Validator — Luhn Check, Brand Detection & Formatting

How to use

About this tool

FAQ

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The complete credit card validator guide