PIN Generator

PIN Security Guidelines

A PIN is only as secure as its length and randomness. Predictable PINs - Like 1234, 0000, or your birth year - Are among the first guesses an attacker will try. Even a 6-digit PIN chosen randomly is exponentially harder to crack than a 4-digit one. Trying every combination like this is the textbook example of a brute-force attack.

• Use 6 digits or more wherever the service allows
• Avoid PINs based on birth dates, phone numbers, or repeating digits
• Never share your PIN via email, SMS, or chat
• Use a different PIN for each account

Time to Crack PIN by Length

Assuming 10 guesses/second (typical hardware PIN brute-force) - For comparison with full passwords, see how long it takes to crack a password.

PIN vs Password vs Passphrase

Type	Example	Entropy (typical)	Best Use
4-digit PIN	7392	13 bits	ATMs, locked screens with rate-limiting
6-digit PIN	491827	20 bits	Two-factor authentication codes
12-char random password	xQ4!mR9#wLz2	79 bits	Online accounts and services
Passphrase (5 words)	purple lamp river song oak	~65 bits	Master passwords, encryption keys

Why Human-Chosen PINs Fail

A four-digit PIN has 10,000 possible values, which sounds adequate until you account for how people actually choose. Analyses of leaked PIN datasets consistently find that a small handful of values cover a disproportionate share of all PINs in use.

• Dates - Birth years cluster hard in the 19xx range, and day-month combinations restrict the first two digits to 01-31.
• Repeats and runs - 1111, 1234, 0000 and their variants are guessed first by every attacker.
• Keypad patterns - 2580 looks random but is simply a straight line down the middle of the keypad.
• Reuse - The same PIN on a phone, a bank card, and a door entry system means one shoulder-surf compromises all three.

A generated PIN has none of these biases: every value is equally likely, so an attacker gains nothing from knowing how humans think.

How Many Digits Do You Actually Need?

Length	Combinations	Appropriate for
4	10,000	Only where the device enforces a hard lockout after a few failures - a phone or a bank card
6	1,000,000	Phone unlock, SIM PIN, anything without aggressive lockout
8	100,000,000	Door entry systems, safes, shared codes that rotate infrequently
10+	10,000,000,000+	Systems with no rate limiting, where offline guessing is possible

The key insight is that PIN length matters far less than whether the system limits guessing. Four digits behind a ten-attempt lockout is stronger in practice than eight digits on a system that allows unlimited tries.

Where a PIN Is the Wrong Tool

PINs work because they guard a physical device or a rate-limited terminal. They are a poor choice for anything an attacker can attack offline or at scale - online accounts, encrypted archives, or password-manager master credentials. For those, use a long generated passphrase instead.

Frequently Asked Questions

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