Security Validators

The Security validators category covers identifiers and values where correctness has direct security or financial implications — passwords, payment card numbers, and mobile device identifiers. These are not just format checks; they involve algorithms (Luhn checksum), scoring systems (password strength), and links to national blacklist databases (IMEI and CEIR).

Password strength

The Password Strength Checker evaluates passwords against the criteria used by most security systems: length, character variety, and absence of trivially guessable patterns. It returns a 0–100 score and a Weak/Fair/Good/Strong classification — giving actionable feedback rather than a binary pass/fail. The tool is useful when setting a new password for a critical account, as a teaching tool for security awareness training, or as a sanity check when reviewing a password policy.

Critically, the tool runs entirely in your browser — your password is never transmitted anywhere.

Payment card validation

The Credit Card Number Validator applies the Luhn algorithm — the checksum that payment networks have used since the 1960s to catch transcription errors. It also identifies the card network from the IIN prefix, covering Visa, Mastercard, Amex, Discover, JCB, Diners Club, and RuPay (India's domestic network issued by NPCI).

The Luhn check is useful for client-side form validation — catching obvious mistyped card numbers before submitting to a payment gateway, which reduces unnecessary API calls and provides faster feedback to users.

Mobile device identity

The IMEI Validator confirms that a 15-digit IMEI is structurally valid using the Luhn algorithm. IMEI format validation is the first step when checking a second-hand phone purchase — before performing a full blacklist check via the government CEIR portal or an operator IMEI check service.

Format vs. authenticity

Like all validators on this platform, these tools check format and structure, not authenticity. A credit card number that passes the Luhn check is not a real card. An IMEI that passes format validation is not guaranteed to be unblocked. A strong password is not inherently safe if it has been reused or exposed in a data breach.

For financial identifier validation (PAN, GST, IBAN, VAT), see the Finance & Global IDs category.