Letter S pattern lock
How to draw the letter S 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 S on a 3×3 grid
The letter S can be drawn exactly on the 3×3 grid in a single stroke, without going back over any line.
- Start at dot 3 (top-right corner).
- Go to dot 2 (top middle).
- Go to dot 1 (top-left corner).
- Go to dot 4 (middle left).
- Go to dot 5 (center).
- Go to dot 6 (middle right).
- Go to dot 9 (bottom-right corner).
- Go to dot 8 (bottom middle).
- Finish at dot 7 (bottom-left corner).
PatternGuard’s analyzer gives it 20/100 (Very weak): 9 dots, 0 crossings, starting at the top-right corner.
On 3×3 this is exactly the same pattern as the number 5: anyone who guesses one has guessed the other.
Is a letter S 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 S, this is one of the first patterns someone who knows you would draw.
A stronger way to use the letter S
On 3×3 the letter S already uses almost every dot, so there’s no room to hide it inside a longer stroke. If you want to keep it, the 4×4 version on this page gives you more room; otherwise, the safest pattern is one of your own that doesn’t spell anything.
The letter S 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 S can be drawn exactly on the 4×4 grid in a single stroke, without going back over any line.
Order: 13 → 14 → 15 → 12 → 11 → 10 → 5 → 2 → 3 → 4
PatternGuard’s analyzer gives it 24/100 (Very weak): 10 dots, 0 crossings, starting at the bottom-left corner.
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.