How Secure Is a PIN?
TL;DR: PIN security is purely about length and randomness. A 6-digit random PIN has 1,000,000 combinations (19.9 bits); a 4-digit PIN has only 10,000 (13.3 bits). Always use the longest PIN your device allows and generate it randomly — never use birth dates or sequences.
PIN Entropy by Length
| Length | Combinations | Entropy | Verdict |
|---|---|---|---|
| 4 digits | 10,000 | 13.3 bits | Weak — avoid if possible |
| 5 digits | 100,000 | 16.6 bits | Moderate |
| 6 digits | 1,000,000 | 19.9 bits | Standard for phones |
| 8 digits | 100,000,000 | 26.6 bits | Strong |
| 10 digits | 10,000,000,000 | 33.2 bits | Very strong |
Most Common PINs to Avoid
Data from leaked PIN datasets (analysis of over 3.4 million exposed PINs) shows humans are highly predictable:
- 1234 — accounts for over 11% of all 4-digit PINs
- 1111, 0000, 1212, 7777
- Birth years (19xx) — especially 1990–2010
- Dates in MMDD or DDMM format (your own birthday)
- Keyboard patterns like 2580 (down the middle column)
Generating a random PIN removes all of these predictable patterns.
FAQ
How secure is a random PIN?
A random 6-digit PIN has 1,000,000 combinations (19.9 bits). A 4-digit PIN has only 10,000 (13.3 bits). Always use the longest PIN your device allows, and never reuse PINs.
What is the most common PIN to avoid?
Avoid 1234, 0000, 1111, 1212, and dates. 1234 alone accounts for over 10% of all 4-digit PINs. Generate a random PIN instead.
Is this PIN generator safe?
Yes. All PINs are generated in your browser using window.crypto.getRandomValues.
No PIN is transmitted or stored.
Should I use a 4-digit or 6-digit PIN?
Use a 6-digit PIN whenever possible. It has 100 times more combinations than a 4-digit PIN.
Related guides: Password Entropy Explained · How Secure Is My Password?
We do not collect, store, or transmit any PIN or password.