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Validate Card Checksum in 2 seconds

Name: Card Checksum Validator
Brand: Finance Tools

Validate Card Checksum card numbers. Luhn checksum, brand detection, length check. Format-only — does not verify activity.

Try live demo ↓ See pricing

GET /card — live demo

Input card checksum

Sample value. Replace with your own.

Validation result

// Click "Validate →" to run

Ready. Free 50 validations/day.

How it works

Credit card numbers follow the Luhn algorithm and brand-specific lengths. Our validator detects the brand from BIN range, checks length and runs Luhn. It does not verify if the card is active or has funds.

API call

# GET
curl "https://finance-validators.boring-saas-infra.workers.dev/card?value=4111111111111111"

# POST (same result)
curl -X POST https://finance-validators.boring-saas-infra.workers.dev/validate \
  -H "Content-Type: application/json" \
  -d '{"type":"card","value":"4111111111111111"}'

What you get back

{
  "valid": true,
  "card_number": "4111111111111111",
  "brand": "visa",
  "luhn_ok": true,
  "length_ok": true,
  "last4": "1111",
  "length": 16,
  "note": "Format-only check. Does not verify if card is active."
}

Why use our card checksum validator

Instant — ~50ms response time from Cloudflare edge.
Format + checksum + country rules (where applicable).
REST API. Works from any language.
Free 50/day. Pro: 5,000/month for $19.99.
No API key needed for the free tier.

Pricing

$0/forever

50 validations / day
All 5 validators
REST API

Start free

$19.99/month

5,000 validations / month
Batch validation
VIES lookup (VAT)
Priority queue

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FAQ

How do I validate a card checksum?

GET /card?value=YOUR_VALUE or POST to /validate with {"type":"card","value":"..."}.

Is there a free tier?

Yes. 50 validations per day, no credit card required.

What does the validator check?

Format, length, country rules, and checksum where applicable.

Can I integrate this via API?

Yes. REST API. GET or POST. Works from any language.

Does it check if a real account exists?

No. Format + checksum only. It does not verify existence or activity.