How to Play Kakuro on kakuro-puzzle.online

Kakuro on kakuro-puzzle.online is a number crossword: fill every white cell with a digit from 1 to 9 so that each across run and each down run adds up to its clue, with no digit repeated inside a single run. You play by selecting a white cell, entering digits with the on-screen number pad, and using notes when you want to mark candidates. The board accepts normal Kakuro entries — you do not type equations or submit words. The site offers Regular (200 levels), Daily (5 puzzles today), and Unlimited (7x7 verified seeds) modes, plus a Battle mode with 3, 5, or 8 puzzle challenges.

The rules you actually need

Four rules cover almost every mistake:

• A clue controls one straight run. A clue in the lower-left triangle of a black cell controls the across run to its right; a clue in the upper-right triangle controls the down run below it. Some black cells carry both numbers and start one across sum and one down sum at the same time. A run ends at the next black cell or the board edge.
• Digits are 1–9 only. No zeros, no multi-digit entries.
• No repeats within a run. A two-cell clue of 4 is 1+3, not 2+2. The same digit can appear elsewhere on the board as long as it belongs to a different run.
• Every white cell serves two clues. Each cell sits in one across run and one down run, so a candidate is only useful if it can satisfy both sums at once.

A solved board has every white cell filled, every across run equal to its clue, every down run equal to its clue, and no repeated digit inside any single run.

Step by step: your first puzzle

1. Find a clue and trace its run. Start from a black clue cell and follow the connected white cells until another black cell or the board edge stops you. That run is the only group the clue controls.
2. List the legal digit combinations. Use digits 1–9 with no repeats. Small sums are the easiest entry point: a two-cell clue of 3 can only be 1+2, and a two-cell clue of 4 can only be 1+3.
3. Cross-check before entering. For each candidate digit, ask whether it also fits the crossing run's sum. A digit that works across but breaks the down sum is not a candidate.
4. Enter digits and mark uncertainty with notes. Select a white cell, press a digit on the number pad, and use the Notes tool to record candidates you have not committed to.
5. Use Check only when ready. The Check button reveals conflicts; pressing it early gives away progress you could have found by logic.
6. Verify at the end. Confirm every white cell is filled, every run matches its clue, and no run contains a repeated digit.

The site's own walkthrough uses a concrete example: a yellow 3 on the left points to the two white cells beside it, which must add to 3 without repeating — so you tap the first highlighted cell and press 1.

Reading the board

Modes and progression

• Regular — 200 levels, starting at Level 1 (Easy). The interface shows filled-cell count (e.g., 0 / 4 filled), a timer, best time, and an issues counter.
• Daily — 5 puzzles today, with daily wins tracked.
• Unlimited — 7x7 verified seeds for open-ended practice.
• Battle — 3, 5, or 8 puzzle challenges.

You can start instantly without an account; signing in with Google later saves progress, best times, and daily wins.

Common sticking points

• Treating a clue as a whole row. A clue stops at the next black cell — it never spans the full grid width.
• Allowing repeats inside a run. This is the most frequent rule error; recheck any run where you entered the same digit twice.
• Ignoring the crossing clue. Entering a digit that satisfies the across sum but breaks the down sum creates a conflict you will have to undo.
• Guessing instead of deducing. The site frames Kakuro as solved by logic rather than guessing; when stuck, return to the shortest runs and the smallest sums, which have the fewest legal combinations.

Quick reference

• Digits: 1–9, no repeats within a run.
• Each white cell must satisfy both its across and down clues.
• Tools: number pad, Notes, Undo, Hint, Check, Reset.
• Start with two-cell runs and low sums; they constrain candidates fastest.