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Credit Card Validator

Validates credit/debit card numbers with the Luhn algorithm and detects the card type.

Data stays in your browser

Ready to runInstant execution

Result

—

What does this tool do?

Validates credit/debit card numbers with the Luhn algorithm and detects the card type.

Why would I use it?

You want to catch typos in card numbers before submitting.
You are testing form validation logic.
You want to know the issuer type from the prefix.

Real-life example

Input

4242424242424242

Output

✓ Valid (Visa)

The Luhn checksum and prefix are verified.

Input → Process → Output → Next

Input: Type a card number.
Process: The browser runs the Luhn checksum and prefix rules.
Output: Valid/invalid plus detected type.
Next action: Use it only for testing — never store real card numbers.

Common mistakes

Thinking Luhn-valid means the card is active.
Testing with made-up numbers that pass Luhn.
Storing or logging real card data (PCI DSS).

What the result means

Luhn-valid means the number is well-formed, not funded.

Privacy & security

Your input is processed entirely in your browser and never sent to a YAS server.

API

Endpoint

POST https://yas.sh/api/v1/tools/credit-card-validator

Request Header

Content-Type: application/json

cURL

curl -X POST "https://yas.sh/api/v1/tools/credit-card-validator" \
  -H "Content-Type: application/json" \
  -d '{"input":"4242 4242 4242 4242"}'

JavaScript

const res = await fetch("https://yas.sh/api/v1/tools/credit-card-validator", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
  "input": "4242 4242 4242 4242"
}),
});
const data = await res.json();

Python

import requests

r = requests.post("https://yas.sh/api/v1/tools/credit-card-validator", json={"input":"4242 4242 4242 4242"})
data = r.json()

Field	Type	Required	Description
input	string	Yes	Digits; spaces/dashes tolerated

Success response

{ "slug": "credit-card-validator", "result": { "valid": true, "scheme": "visa", "note": "Luhn checksum only" } }

Luhn checksum + scheme detection (NOT an existence check).

Error responses

400 VALIDATION_ERROR — invalid input or unsupported option.
413 PAYLOAD_TOO_LARGE — input exceeds the 64 KB limit.
429 RATE_LIMIT_EXCEEDED — rate limit exceeded (60 req/min).

Limits

Maximum input: 64 KB per request.
Rate limit: 60 requests/min per IP address.
Authenticated accounts benefit from higher tier quotas.

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MAC Validator