TappyPotato logic puzzles

Pencil logic

Akari — rules and where to play

AKARI · Light Up / Bijutsukan

Place bulbs on white cells until every cell is lit. Numbered black cells are walls; the digit says how many bulbs touch them.

Origin
2001 · Japan
Difficulty
★★★★★ 2–4 / 5
Time
5–30 min
Grid
7×7 – 25×25
Sites
9

Rules

  1. A bulb lights straight up, down, left and right until a black cell blocks it.
  2. Every white cell must end up lit.
  3. No bulb may see another bulb — two bulbs never share an unblocked line.
  4. A numbered black cell needs exactly that many bulbs on its four sides.

How to start

Start on the 4s and 0s

All four neighbours filled or all four empty: one move settles a block.

Dead sides of a clue are free information

If a numbered cell has no white neighbour on one side, that side can never hold a bulb.

Use "must not be seen" in reverse

A cell where a bulb would be seen by another bulb is empty. It is the sharpest tool in crowded areas.

Where players get stuck

  • Forgetting bulbs cannot see each other, then hitting conflicts across a whole region.
  • Watching only the clues and forgetting every white cell must be lit.

Play Akari

9 sites
Puzzle PicnicFree

Handmade Nikoli-style grids from a mix of setters, picked rather than dumped, playable in the page.

Open → PuzzleMixFreemium

Gareth Moore's site: Sudoku, then Slitherlink, Nurikabe, Futoshiki, Calcudoku and Hanjie.

Open → pzv.jpFree

A wider puzz.link-style database — more types, cut a bit finer.

Open → Penpa+Free

A fat editor for Japanese types: lots of shapes and marks, and it will ingest a puzz.link.

Open → pzplusFree

A community bank with difficulty and clear counts, browsable without leaving the page.

Open → Naoki InabaFree

Naoki Inaba writes a lot, including types you won't see many other places.

Open → Puzzle Square JPFree

A large Japanese variant archive that moves often, with difficulty marks on the grids.

Open → Grandmaster PuzzlesFree

Thomas Snyder's own handmade Sudoku and variants — world-champion difficulty, not generated filler.

Open → GridPuzzleFree

Dozens of grid logic types in the browser, with progress tracking and dailies.

Open →

Browse All-in-one portals →

Also on multi-type portals

Janko.atFree

Otto Janko's German/English archive: hundreds of playable types, all free.

Open → Puzzle RulesFree

Clean rule pages for dozens of types. Fastest way to learn a grid you haven't seen.

Open → NoqxFree

An ASP solver for 170-plus types. Connectivity puzzles tend to come back quickly.

Open → Nikoli Puzzle SolverFree

Z3 under the hood, 100-plus types, including hex and triangle boards.

Open →

Browse portals →

Related puzzles

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About this page
  • Last updated 2026-09-22
  • Source Curated compilation of established puzzle rules and listed third-party play sites
  • Audience Players learning Akari rules or looking for online sites to play
  • Covers Rules summary, how to start, common pitfalls, and the dedicated play sites listed on this page
  • Does not cover Hosted puzzles, worked solutions, official contest rankings, third-party uptime or pricing guarantees
  • Not advice This page is puzzle reference content only. It does not constitute financial, legal, medical or other professional advice.
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