Letter J pattern lock
How to draw the letter J as an Android unlock pattern, step by step, on the standard 3×3 grid and on 4×4, with the security score PatternGuard’s analyzer gives each version.
The letter J on a 3×3 grid
The letter J can be drawn exactly on the 3×3 grid in a single stroke, without going back over any line.
- Start at dot 1 (top-left corner).
- Go to dot 2 (top middle).
- Go to dot 5 (center).
- Go to dot 8 (bottom middle).
- Finish at dot 7 (bottom-left corner).
PatternGuard’s analyzer gives it 5/100 (Very weak): 5 dots, 0 crossings, starting at the top-left corner.
Is a letter J pattern safe?
Not really. Letters are among the first shapes anyone tries: research on real-world patterns found that about 1 in 10 is shaped like a letter, often the initial of a partner or a child (Løge, 2015). If your name or your partner’s name starts with J, this is one of the first patterns someone who knows you would draw.
A stronger way to use the letter J
If you like the letter J, don’t draw it on its own. Adding 1 dot before it and 1 after it keeps the shape you remember but hides it inside a longer stroke: 6 → 1 → 2 → 5 → 8 → 7 → 3 scores 46/100 (Moderate), against 5 for the plain letter J.
It’s still published here, so treat it as an example of the idea, not as a pattern to copy. The safest pattern is one of your own that doesn’t spell anything.
The letter J on a 4×4 grid
Stock Android uses the 3×3 grid; 4×4 shows up in some custom ROMs and lock-screen apps, and the simulator supports it. The letter J can be drawn exactly on the 4×4 grid in a single stroke, without going back over any line.
Order: 2 → 3 → 4 → 8 → 12 → 15 → 14 → 9
PatternGuard’s analyzer gives it 31/100 (Weak): 8 dots, 0 crossings, starting at the row 1, column 2.
Why some letters can’t be drawn exactly
Android’s pattern lock has three rules: at least 4 dots, no dot can be selected twice, and if the stroke passes over a dot you haven’t used yet, Android adds it automatically. Passing over a dot you already used is allowed, which is how letters like P, R or F can be traced exactly. On 3×3, shapes with a closed loop or three or more loose ends (like A, B or O) still need one line left out or one line added; the 4×4 grid has more room, but not always enough.