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security validator

Credit Card Validator

Run a local Luhn check to confirm card number format before hitting payment APIs—no data leaves your browser.

Results

Processing…
Status
Processing...
Details
Processing...

How to use this validator

  1. Paste or type the card number (use test PANs).
  2. Run validate to strip formatting and apply the Luhn check.
  3. If invalid, recheck for missing digits or transposed numbers.

Rules & checks

Strips spaces and non-digits before validating.

Applies the standard Luhn checksum to detect transpositions/typos.

No issuer/brand detection; no network calls or storage.

Inputs explained

  • Card number

    Paste a test card number. We strip spaces/dashes automatically. Use network-provided test numbers, not production PANs.

When to use it

  • Pre-validate card numbers client-side before tokenization
  • QA billing flows with network-provided test cards
  • Triage support tickets for obvious entry mistakes

Common errors

  • Missing digits after copy/paste
  • Transposed adjacent numbers
  • Hidden whitespace or non-digit characters
  • Using real PANs instead of test cards

Limitations

  • Format/checksum only—does not verify funds, issuer, BIN, or risk.
  • No brand detection; no AVS/CVV checks.
  • Do not use with production PANs; keep validation on tokenized flows.

Tips

  • Always use payment provider test cards in non-production.
  • Strip non-digits before sending to your payment gateway.
  • Even if Luhn passes, still tokenize and validate server-side.

Examples

Valid (Visa test)

  • 4242 4242 4242 4242 -> Passes Luhn

Valid (Amex test)

  • 3782 822463 10005 -> Passes Luhn

Invalid: fails checksum

  • 1234 5678 9012 3456 -> Fails Luhn

Invalid: wrong length

  • 4242 4242 4242 -> Fails (too short)

Deep dive

This credit card validator runs the Luhn checksum in your browser to catch typos in card numbers before you hit payment APIs.

Use provider test PANs only; even with a pass, you must tokenize and validate on the server for real transactions.

FAQs

Is my card number uploaded or stored?
No. Everything runs locally and clears on refresh—use test cards only.
Does this identify card brands or BINs?
No. It only checks the checksum/length. Use your gateway for brand/BIN detection.
Does a Luhn pass mean the card will charge?
No. It only confirms format. Always tokenize and run gateway validations for real payments.
Can I check CVV/AVS here?
No. Those are server/gateway checks. This is format-only.

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