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credit-card-validator

A credit card validator runs Luhn-checksum validation on a card number, identifies the issuer (Visa, Mastercard, Amex, Discover, JCB, Diners Club, UnionPay) by prefix and length, and optionally looks up the bank-identification number (first 6 digits) against a public BIN database to surface the issuing bank, country, and card type (credit / debit / prepaid). The ZTools Credit Card Validator runs entirely in the browser, validates bulk lists, and is the right pre-flight check for QA, fraud-rule development, and form validation — never use it on real customer card numbers in production logs.

Use cases​

Frontend form validation​

Checkout form rejects mistyped card numbers before submitting to the PSP — fewer round-trips, better UX, fewer false declines.

Fraud-rule development​

Anti-fraud team writes BIN-prefix rules. Use this validator to inspect issuer / country / type from a list of test BINs.

QA and synthetic test sets​

Pair with the Credit Card Generator: generate Luhn-valid test numbers, run them through the validator to confirm your form parses correctly.

Receipt/invoice validation in your pipeline​

A reconciliation pipeline reads PAN-redacted strings; validate the masked-style format ("•••• 4242") for plausibility.

How it works​

  1. Paste card number(s) — Single or bulk. Spaces and dashes are stripped automatically.
  2. Luhn checksum — Standard mod-10 algorithm. Verifies the last digit matches the rest.
  3. Issuer detection — Prefix + length match: Visa starts 4 (13/16/19); MC 51–55 or 2221–2720 (16); Amex 34/37 (15); Discover 6011/65 (16); JCB 35 (16); Diners 30/36/38 (14).
  4. Optional BIN lookup — First 6 digits queried against a free, public BIN database. Returns issuing bank, country, type. Skip if offline.
  5. Inspect results — luhn_valid, issuer, length_ok, bank, country, card_type. Bulk results export to CSV.

Examples​

Input: 4242 4242 4242 4242

Output: luhn=true, issuer=Visa, length=16, BIN=Stripe test card

Input: 5555 5555 5555 4444

Output: luhn=true, issuer=Mastercard, length=16

Input: 4242 4242 4242 4243

Output: luhn=false (failed checksum)

Frequently asked questions​

Does Luhn validation prove the card is real?

No — Luhn only proves the digits self-consistently. A Luhn-valid number can still be unassigned, expired, frozen, or stolen. Authorisation requires a payment-processor call.

Should I store full card numbers?

No, never. PCI-DSS forbids it for non-compliant systems. Frontend validators should pass the number directly to your PSP's tokenization SDK; your servers should never see it.

Is the BIN lookup live?

Yes — calls a public BIN-DB API. Free tier is rate-limited; for high-volume use, integrate a paid BIN service in your backend.

Are 19-digit Visa cards supported?

Yes — Visa allows 13, 16, or 19 digits. The validator detects the length and confirms checksum.

Is data uploaded?

Luhn + issuer detection are fully local. BIN lookup hits a public API only when you opt in.

How does this differ from a real authorisation check?

Authorisation is a card-network call that confirms the account exists, has funds, and is not frozen. The validator does only static checks; authorisation needs your PSP.

Tips​

  • Use this validator on the frontend to catch typos early; never log full PANs.
  • For PCI-DSS scope reduction, send card data directly from the user's browser to your PSP's tokenizer — your servers should only ever see tokens.
  • BIN-based fraud rules are powerful (block known prepaid BINs in high-risk regions) — use the BIN lookup to build the lists.
  • Validator output is metadata; always wait for the PSP authorisation before fulfilling the order.
  • For QA fixtures, prefer your PSP's documented test card numbers over generated Luhn-valid ones — they exercise specific simulated flows.

Try it now​

The full credit-card-validator runs in your browser at https://ztools.zaions.com/credit-card-validator — no signup, no upload, no data leaves your device.

Open the tool ↗

Last updated: 2026-05-05 · Author: Ahsan Mahmood · Edit this page on GitHub