How to get faster at sudoku

Almost everyone answers this with "practice more." That's true and useless. The useful version is: practice the right things, in the right order, and stop doing the two things that quietly cost you the most time. Speed is efficiency, not hurry — fast solvers aren't rushing, they've removed the wasted movements.

The one idea: take the cheapest move, always

Here's how Speedoku's engine grades difficulty, and it's also the single most useful model for solving fast. At every step, there's a cheapest technique that applies — the easiest deduction the board currently allows. A hidden single is cheaper than a naked pair, which is cheaper than an X-Wing. Our solver always plays the cheapest applicable technique, and so should you.

Slow solvers do the opposite. They lock onto one hard-looking cell and stare at it, hunting for the answer, while three trivial singles sit unplaced elsewhere on the board. The fix is a mindset flip: don't look for the answer to a cell, look for the easiest legal move anywhere on the grid. Take it. The board opens up, and the cell you were stuck on often solves itself two moves later.

Make the bottom of the ladder automatic

There are only a handful of techniques you use in almost every puzzle, and they're the cheap ones. Fast solving is not about knowing more techniques — it's about recognizing the common ones instantly, with no conscious effort. Drill these until they're reflexes:

• Hidden singles — a digit that can legally go in only one cell of a box, row, or column, even if that cell shows several candidates. This is the workhorse of fast solving; most of your placements are hidden singles.
• Naked singles — a cell where only one digit is possible. Cheap to place, but slower to find without marks, so you catch these on your row/column sweep.
• Naked and hidden pairs — two cells locked to the same two candidates (or two digits locked to the same two cells). They don't place a number, they eliminate candidates elsewhere and unlock the next single.
• Pointing pairs (locked candidates) — when a digit inside a box is confined to one row or column, it clears that digit from the rest of that line. Cheap, common, and constantly overlooked by intermediate solvers.

That's the entire toolkit for the majority of puzzles you'll solve for speed. Full definitions and worked examples live in the techniques guide, ranked by difficulty.

Build a fixed scanning route

The biggest single speed gain for most people isn't a technique — it's a routine. A random scan is slow because you re-check the same box you looked at ten seconds ago and skip the one you never reached. Commit to one route and run it the same way every time:

1. Take each digit, 1 through 9, and scan all nine boxes for a hidden single of that digit. This finds most of your placements.
2. Sweep rows top to bottom, then columns left to right, for naked singles and any obvious pairs.
3. Look for locked candidates — a digit pinned to one line inside a box — and make the eliminations.
4. Every time you place a digit, immediately re-scan its row, column, and box before moving on. A placement is the moment new deductions become possible; that's where the next move usually is.

Which exact order you pick matters far less than picking one and running it until it's automatic. The goal is to never spend a half-second deciding where to look.

The counterintuitive part: advanced techniques won't make you faster

Intermediate solvers plateau and assume the next level is learning swordfish, XY-wings, and coloring. For speed, that's backwards. Those techniques appear rarely, they're expensive to spot, and time spent hunting for an X-Wing that isn't there is time not spent placing the singles that are. A puzzle that requires a technique above pointing pairs is, by definition, a hard puzzle — and hard puzzles are a small slice of what you'll ever solve against the clock.

Learn the advanced techniques for completeness — so a genuinely hard grid doesn't stop you cold. Don't learn them for speed. Your fastest gains, by a wide margin, come from making hidden singles and pointing pairs instant. This is also why difficulty and technique are linked: the hardest technique a puzzle forces you to use is a direct readout of how hard it is. Speedoku grades every puzzle exactly this way.

How fast is fast?

A sense of scale, for a practiced (not competitive) solver. Treat these as rough bands, not targets — the only number that matters is your own trend over weeks:

Beginners commonly run two to three times these bands, and that's normal — the times fall on their own as scanning becomes routine. Competitive solvers clear easy grids in under two minutes, but they got there by making the cheap techniques reflexive, not by learning exotic ones.

A practice plan that actually builds speed

• Practice at the edge of easy. Solve puzzles one notch below where you start struggling. You're grooving recognition, not grinding through pain. Speed is built on volume of clean reps.
• Time every solve. Not to race — to see your trend and spot the puzzle types that cost you. You can't improve a number you don't watch.
• Review the moment you got stuck. After a slow solve, find the point where you stalled and ask what the cheapest available move was. Nine times out of ten it was a single you scanned past.
• Play under a little pressure. A timed, one-shot format trains you to commit to moves instead of second-guessing — the habit that separates fast solvers from careful ones.

That last point is the whole idea behind Speedoku: time is the score, and one wrong-but-legal move can corner the board, so you learn to place fast and place deliberately. It's the most direct speed drill we know of. The Daily Challenge gives everyone the same board once a day — a clean way to benchmark your pace against a fixed puzzle.