Play Hashi Pro Online: The Ultimate Bridge-Building Puzzle

If you love Sudoku or Nonograms, it’s time to test your brain with Hashi Pro.

Originally known as Hashiwokakero (meaning “build bridges” in Japanese), this highly addictive logic puzzle requires you to connect a grid of scattered islands into one single, massive network.

No math is required—just pure logic, deduction, and a bit of strategy.

How to Play Hashi (Rules for Beginners)

The goal of Hashi is simple: connect all the islands (the circles) by drawing bridges between them. However, you must follow a strict set of rules to solve the board:

1. Check the Numbers: The number inside each island tells you exactly how many bridges must be connected to it.
2. Straight Lines Only: Bridges can only be drawn horizontally or vertically. Diagonal bridges are not allowed.
3. No Crossing: Bridges cannot cross over each other, and they cannot cross over other islands.
4. Double Bridges: You can connect two islands with either one or two bridges, but never more than two.
5. One Connected Network: By the end of the puzzle, every single island must be connected to the same continuous network. You cannot have isolated groups of islands.

(To play the game above, simply click an island to select it, then click an adjacent island to build a bridge. Click again to make it a double bridge, and click a third time to remove it!)

Winning Strategies: How to Solve Hashi Puzzles

If you are just starting out, staring at a board full of numbers can feel overwhelming. Here are three pro tips to get you unstuck:

1. Look for the “Forced” Bridges First

Always start with the corners and edges.

• A 4 in the corner can only connect in two directions. Therefore, it must have two double bridges. Fill those in immediately!
• A 6 on the edge can only connect in three directions. It must have three double bridges.
• An 8 anywhere on the board must have four double bridges (the maximum allowed).

2. The “Plus One” Rule

If you have a 3 in a corner, it has to connect to its two neighbors. Even if you don’t know which neighbor gets the double bridge, you know for sure that both neighbors will get at least one bridge. Draw those single bridges to give yourself a visual starting point.

3. Avoid Early Isolation

Remember the golden rule: all islands must eventually connect. If drawing a bridge would create a closed-off mini-network that doesn’t include the rest of the board, that bridge is a mistake. Keep the pathways open!

What is Hashiwokakero?

Hashiwokakero was popularized by Nikoli, the same Japanese puzzle publisher that brought Sudoku to the masses. While it looks like a math game, it is actually a topological puzzle. Playing Hashi daily is an excellent way to improve your spatial reasoning, patience, and problem-solving skills.