Are Wordplay PINs Risky? Easily Guessed 4-Digit Codes and How to Choose a Safe One
Have you ever picked a PIN because it spells something, like 5683 (L-O-V-E on a phone keypad) or a number that reads as a word in Japanese? Memorable numbers are handy, but they're also easy for others to think of. A 4-digit PIN has only 10,000 possibilities, 0000 to 9999, and if an attacker tries the most common ones first, it can be guessed far sooner than you'd expect. This article covers the 4-digit patterns that are easy to guess, why wordplay numbers are risky, how to choose a PIN that's still easy to remember, and how to check your own.
4-digit PINs are tried in order of popularity
A 4-digit PIN has 10,000 combinations, 0000 to 9999. Trying them all in order would take 5,000 attempts on average, but the numbers people actually choose are heavily skewed. A study of leaked PINs (DataGenetics, 2012) found that 1234 alone made up about 10% of the total, and just the top 20 accounted for more than a quarter.
Bank cards and smartphones lock after a few wrong attempts in a row, so someone else can only guess the numbers they can try in those few attempts. Put the other way round, if you just avoid the "common numbers" that get tried first, the chance of a 4-digit PIN being guessed drops sharply. The danger lies less in the small number of digits than in how skewed people's choices are.
4-digit patterns that are easy to guess
The numbers tried first follow a few set patterns. The PIN check in the Japanese Number Wordplay Maker looks for exactly these patterns.
| Pattern | Examples | Tool's verdict |
|---|---|---|
| Repeated digits | 0000, 1111, 7777 | Easy to guess |
| Sequences (up or down) | 1234, 4321, 9876, 0123 | Easy to guess |
| Vertical or diagonal lines on the keypad | 2580, 1478, 1590 | Easy to guess |
| Famous wordplay numbers | 4649, 1122, 2525 | Easy to guess |
| A repeated pair | 1212, 3434 | Somewhat easy to guess (especially common ones such as 1212 are easy to guess) |
| Palindromes | 1221, 3443 | Somewhat easy to guess |
| Calendar years | 1987, 2024 | Somewhat easy to guess (birth years, anniversary years) |
| Month and day | 0101, 1225, 0214 | Somewhat easy to guess (birthdays, anniversaries) |
| Numbers that read as words | 4510 (shigoto, "work"), 3874 (saba nashi, "mackerel, pear") | Somewhat easy to guess |
2580 is the line straight down the middle of a phone or ATM keypad: 2, 5, 8, 0. Even if the number itself means nothing, numbers with simple finger movements are used a lot, so they count as easy to guess.
3 reasons wordplay numbers are risky
- Famous wordplay numbers occur to everyone: in Japanese, 4649 reads as yoroshiku ("nice to meet you"), 1122 as ii fūfu ("good couple") and 2525 as niko niko ("smiley"). In English, keypad words such as 5683 (LOVE) work the same way. Because they're easy to remember, many people choose them, so even if the digits look random, they get tried as "common numbers".
- Wordplay tied to you can be looked up: numbers based on your name, favorite food or pet's name can be guessed from social media posts or conversation.
- Wordplay numbers tend to be reused elsewhere: if you use a wordplay number for a custom license plate or phone number, it's tempting to use the same 4 digits as your PIN. License plates and shop phone numbers are visible to anyone.
Checking with the Japanese Number Wordplay Maker, 4649 matches both "a well-known common 4-digit number" and "reads as wordplay", and is rated "easy to guess (better avoided)". 1122 matches three: a common number, the date 22 November, and the "good couple" wordplay.
How to choose a PIN that's easy to remember but hard to guess
Choosing at random is safest, but if you can't remember it you'll write it down, which is riskier still. To make a PIN hard to guess while keeping it memorable, use the following approach.
- 1
Let chance pick the number
Roll a die four times, or use the PIN setting of a password generator: some method your own ideas don't enter into. Avoid numbers based on your name, birthday, family, pets or address.
- 2
Rule out weak patterns with a check
Check that the 4 digits don't match repeated digits, sequences, dates, years or wordplay, and if they do, pick again.
- 3
Make up a way to remember it afterwards
Once the number is decided, remember it through the shape of the digits, the finger movement, or wordplay or images only you understand. The point is not to build the number from wordplay, but to add a memory aid to a number chosen by chance.
- 4
Don't reuse it
Use different numbers for your bank card, credit card and smartphone. Also avoid numbers matching your license plate, phone number or postcode.
Running the Japanese Number Wordplay Maker's check over all 10,000 numbers from 0000 to 9999, 6,251, about 60%, come out as "no obvious weakness". Nearly 40% of numbers chosen by chance still match some pattern, so the sure approach is to check once after choosing and pick again if it matches.
If, like a smartphone, you can use 6 or more digits, just adding digits multiplies the combinations by 100 or more. How to create strong credentials including passwords is explained in How to create a strong password, and how to balance memorability and strength in How to make a passphrase.
Check whether your PIN is easy to guess
Enter 4 digits in the "Plate & PIN" tab of the Japanese Number Wordplay Maker, and it shows on a three-level scale how easy the number is to guess as a PIN. The check runs in your browser the moment you type; the number is never sent to a server.
| Verdict | Conditions | Examples |
|---|---|---|
| Easy to guess (better avoided) | Repeated digits, sequences, common 4-digit numbers | 0000, 1234, 2580, 4649 |
| Somewhat easy to guess | Repeated pairs, palindromes, years, dates, reads as wordplay | 1225, 1987, 0510 |
| No obvious weakness | None of the above | 7391, etc. |
Numbers with good wordplay are best used not for PINs but for numbers you want people to remember. Ideas are in Choosing a custom license plate number in Japan and Wordplay for phone numbers.
FAQ
- Is it OK to use a wordplay number as a PIN?
- Not recommended. Famous wordplay numbers such as 4649 (yoroshiku) or 1122 (ii fūfu) in Japanese, or keypad words like 5683 (LOVE), are chosen by many people, so they're among the first numbers tried. Wordplay on your name or birthday can also be guessed from your personal details.
- Which PINs should I avoid?
- Repeated digits (0000, 1111), sequences (1234, 9876), vertical keypad lines (2580), repeated pairs (1212), your birth year or birthday, famous wordplay numbers, and numbers matching your license plate or phone number.
- What are the most commonly used PINs?
- An overseas study analyzing leaked PINs found that 1234 made up about 10% of the total, followed by 1111, 0000, 1212, 7777 and others. The top 20 alone reportedly accounted for more than a quarter.
- How do I make a PIN that's easy to remember and safe?
- Choose the number by chance, such as with a die, check that it doesn't match repeated digits, sequences, dates, years or wordplay, and then make up your own way to remember it afterwards. Building a number from wordplay tends to pull it towards common numbers. Use a different number for each card and smartphone.
- Why is using your birthday as a PIN risky?
- Because a birthday is easy for others to find out, from a driver's license, health insurance card or social media profile. If you lose your wallet with your cards in it, the ID in the same wallet reveals your birthday.
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