About WebHashi

What is Hashi?

Hashi — also called Bridges or Hashiwokakero (橋をかけろ), meaning "build bridges" — is a logic puzzle played on a grid of numbered islands. Each island displays a number from 1 to 8, and your goal is to connect all the islands with exactly that many bridges. Bridges run horizontally or vertically, cannot cross each other, and when you're done, every island must be part of a single connected network.

No guessing required. Every Hashi puzzle has a single solution that can be reached through pure logical deduction — a quality that makes it deeply satisfying to solve and impossible to finish by accident.

A puzzle born in Japan

Hashi was invented by the Japanese puzzle publisher Nikoli (ニコリ), first appearing in their magazine in 1990. Nikoli occupies a unique place in puzzle history — they are also responsible for popularizing Sudoku, Kakuro, Nonograms, and dozens of other logic puzzle formats that have since spread around the world.

The company was founded in 1980 and named after a racehorse. Their approach to puzzle design has always emphasized elegance over complexity: a good Nikoli puzzle should be solvable through observation and deduction alone, with no arithmetic, no specialized knowledge, and no luck involved. Hashi embodies that philosophy completely.

In Japan, logic puzzles occupy a cultural space that goes beyond casual entertainment. Puzzle magazines are a fixture of commuter culture — a quiet, focused activity well-suited to the rhythms of train travel and the Japanese aesthetic of ma (間), the value of negative space and deliberate pause. Hashi, with its sparse grid and patient demands, fits naturally into that tradition.

Why we built this

WebHashi exists because Hashi deserves a better home on the internet. Most puzzle sites treat it as an afterthought — a single difficulty level, a handful of puzzles, no real depth. We wanted something closer to what the puzzle actually is: a daily practice, a quiet challenge, a small ritual you can look forward to.

The site offers three grid sizes — 7×7, 10×10, and 15×15 — with new puzzles at every difficulty level each day. There are over 1,800 puzzles in the archive, all generated to be uniquely solvable through logic alone. Nothing is recycled, nothing is random, and every puzzle has been verified to have exactly one solution.

It is free, ad-light, and built to work well on a phone. We hope it becomes part of your morning.

How the puzzles are made

Every puzzle on WebHashi is generated using a solution-first approach: we build a valid bridge network first, then derive the island numbers from it. This guarantees that each puzzle has exactly one correct solution. The generator is tuned to produce puzzles with balanced difficulty — easy puzzles yield quickly to a methodical scan, while hard puzzles require tracking connectivity across the whole grid.

Difficulty is calibrated by the number of logical deduction rounds required to reach the solution — not by arbitrary labels. An easy puzzle on WebHashi is genuinely approachable. A hard puzzle will make you think.