Play Hashi Online: Bridges Puzzle Rules and Strategy
Hashi is a number puzzle about building connections. A scattered collection
of islands becomes a single network, one bridge at a time. The numbers give
you local information, while the shape of the board asks you to think about
the whole network. That combination makes a small puzzle approachable and a
large puzzle surprisingly absorbing. Play Hashi online here with four
difficulties, four board sizes, daily games, hints, undo, redo, and saved
progress.
You may also know this game as Bridges or Hashiwokakero. It belongs to the
pencil-and-paper logic puzzle tradition: the clues stay fixed, and the
answer emerges through deductions. There are no opponents, resources to
collect, or reflex tests. You can take your time, listen to music, and work
through one area before returning to the rest of the board.
How to Play Hashi
Your goal is a connected bridge network that satisfies every island. A
numbered circle is an island; its number tells you how many bridges must
touch it. A single line contributes one to each endpoint, and a double line
contributes two. Bridges travel straight across a row or column between
neighboring islands. They cannot cross, run diagonally, or jump over another
island. There can be no more than two bridges between the same pair. All
islands must belong to one connected network. These are the core Hashiwokakero rules published by Nikoli.
Controls for the Online Bridges Board
Click the space between two neighboring islands to cycle through no bridge,
a single bridge, a double bridge, and back to no bridge. Right-click clears
both bridges at once. This means you can correct a placement without
changing any of the island clues. Use the mouse wheel, background dragging,
or trackpad gestures to move around a large board. The zoom menu and
center-board action help you return to a comfortable view.
For keyboard play, use the arrow keys or WASD to move the selected bridge.
Press 1 for a single bridge, 2 for a double bridge, and Delete or Backspace
to clear it. Space cycles its count. H reveals a hint. The controls dialog
shows your configured shortcuts, including undo, redo, zoom, and centering.
You can adjust shortcuts through the shared game controls.
Your First Hashi Puzzle
Start with easy 7x7 and look for an island with few possible neighbors.
Before adding a line, identify what it would mean for both endpoints. After
placing it, count the bridges touching each endpoint again. A double bridge
is two contributions even though it occupies one direction. Continue around
the board rather than expecting to finish the first island you inspect. A
useful deduction often appears after you complete a different area.
Beginner Hashi Strategy: Count Capacity
The best opening question is often how much an island can receive. Each
visible direction offers a capacity of two. An island with one neighbor and
a clue of 2 needs a double bridge to that neighbor. If an island has two
available directions and a clue of 4, both directions must carry doubles.
These deductions follow from capacity, without needing a guess about the
rest of the puzzle.
You can use the same reasoning even when a number falls below the maximum.
Suppose an island needs five bridges and has three directions available. Two
directions can provide at most four between them, so the third direction
must supply at least one. That argument applies to every direction around
the island. You have established three single bridges; later deductions
determine which become doubles. Think in terms of minimum contributions as
well as final answers.
Recalculate After Every Placement
Capacity changes as the puzzle develops. A completed neighbor cannot accept
additional bridges. A crossing line can remove a direction entirely. An
island that originally had four possible neighbors might eventually have
only two useful directions left. When you make a bridge, revisit nearby
islands and the corridors that line passes across. This habit turns one
placement into a chain of smaller deductions.
A completed island gets a thicker outline and a small underline, so its
status remains visible without relying on color. Too many bridges show an
error. In colorblind mode, an additional mark helps identify an overloaded
island. These indicators are useful checks, but they do not replace
counting: a clue may be locally satisfied while its surrounding network
still needs correction.
Advanced Bridges Strategy: Think About Connectivity
Matching every number is only part of solving Hashi. A board with two
separate, perfectly counted networks is unfinished. Track connected groups
as you work. If a group has only one possible connection to the rest of the
islands, that connection must exist. It may not yet be clear whether it
needs one bridge or two, but you can establish the first bridge immediately.
A particularly useful warning sign is a small cluster about to use all its
remaining capacity internally. Before completing that cluster, check how it
can reach the outside. If every island inside would be full, the placement
would permanently isolate it. You can reject that arrangement even when
every local number looks reasonable. Connectivity reasoning is often what
separates a difficult Hashi puzzle from a straightforward counting exercise.
Crossings as Deductions
Long corridors influence distant parts of the board. A confirmed horizontal
bridge eliminates every vertical bridge that would intersect it, and the
reverse is also true. Follow that consequence to the endpoints of each
eliminated corridor. An island may now have exactly enough capacity left,
forcing a double bridge elsewhere. On a large board, zoom out occasionally
to see these relationships instead of focusing exclusively on one corner.
Testing an Assumption Carefully
When simple counting stalls, choose a narrow question: whether one
particular connection exists, or whether an existing single must become a
double. Follow its consequences until you reach a contradiction or useful
information. Undo lets you return through the trial, and redo lets you
inspect the same steps again. Keep the assumption small so you can remember
why each later placement followed from it. Randomly filling several
corridors usually makes the board harder to understand.
Board Sizes and Four Difficulty Levels
Choose 7x7, 10x10, 15x15, or 25x25 independently of difficulty. A larger
board gives the puzzle more room for islands and longer connections, but
size alone does not describe the solving challenge. A small puzzle can still
require attention to connectivity. Large boards benefit from camera movement
and the magnifying glass, especially when you want an overview without
making individual numbers uncomfortable to read.
Easy puzzles use sparse island layouts and are accepted only when the
generator's counting and crossing propagation resolves them without search.
Medium puzzles increase island density and offer more interacting
possibilities. Hard puzzles use denser networks, with more corridors to
compare and eliminate. Very hard puzzles use the densest target layouts and
additionally require search in the generator's solver. Difficulty is a
practical generation guide rather than a promise about how long an
individual player will take.
The generated collection is checked for a unique connected solution. The
solution is also used by hints, while completion checks the actual bridge
rules. Each size and difficulty has its own random-game collection. Daily
games provide a shared puzzle for a date and rotate through the available
variants, giving you a reason to try a board outside your usual preferences.
Hints, Undo, Redo, and Scoring
A hint corrects the selected bridge when it differs from the solution;
otherwise it chooses another bridge that needs correction. The highlighted
connection shows where the change happened. Take a moment to examine both
endpoint numbers and nearby crossing corridors. A hint is most useful when
it teaches you which restriction you overlooked, instead of simply supplying
a line to copy.
Undo and redo preserve your bridge history. They change placements, while
the action count records the work you have done. Hint usage remains recorded
after undo, so removing the revealed line does not remove its score penalty.
Restarting the current puzzle retains the accumulated penalty and adds a
restart charge. A fresh random game starts its own score record.
Lower scores rank better. Your score is elapsed whole seconds, plus 60 for
every hint, plus accumulated restart penalties. Restarting carries the
current score forward and adds 60. This rewards faster solutions while
keeping assistance visible in the result. Compare scores within the same
size and difficulty; the time needed for a sparse 7x7 and a dense 25x25 is
naturally different. Stats also show your completed games and solving times.
Common Hashi Mistakes
- Counting neighbors instead of bridges. A double contributes
two at each endpoint. Count lines, not just connected circles.
- Completing a disconnected cluster. Leave a route to the rest
of the board. Exact local totals cannot rescue an isolated network.
- Ignoring the far endpoint. Every placement affects two clues.
Check the remaining capacity at both ends.
- Overlooking a blocked corridor. A bridge elsewhere can invalidate
a connection you considered earlier.
- Making several guesses together. Test one assumption at a time
so undo returns you to a position you understand.
Hashiwokakero and the Logic Puzzle Tradition
Nikoli publishes Hashiwokakero as an islands-and-bridges puzzle. Its appeal
comes from combining simple numerical clues with a spatial network. Unlike a
puzzle where each square receives a digit, a Bridges board asks you to
reason about relationships between positions. The empty space matters: a
long corridor can influence several other possibilities before either
endpoint is finished.
If you enjoy the way small restrictions combine into a complete solution,
try Binario for binary balance and line uniqueness,
or Kakuro for intersecting sums. Each game encourages a
different kind of counting. Returning to Hashi afterward can make its connectivity
requirement easier to notice, because you recognize that matching the numbers
is just one layer of the puzzle.
Frequently Asked Questions About Hashi
Can bridges bend or run diagonally?
No. Each bridge is a straight horizontal or vertical connection to a
neighboring island. A turn would create a different kind of path puzzle.
Can two bridges between one pair connect separate networks?
They connect the same endpoints, so they provide one route between those
islands while contributing two to each clue. The second line helps satisfy
totals; it does not reach another island.
Why is the game unfinished when all the numbers match?
Check for separate groups of islands or crossing bridges. The final board
must satisfy the counts, geometry, and connectivity together.
Can I continue a puzzle later?
Enable “Start game from where you left off” in settings. The game uses the
site's saved-game system to preserve your board and undo history. The
magnifying glass and colorblind options are in the same dialog.
Which difficulty should I choose?
Begin with easy 7x7 until capacity deductions feel familiar. Move to medium
or hard when you want more interacting corridors, and try very hard when you
enjoy checking assumptions and network connections. Choose a larger size
when you want a longer session.
Start your next Hashi board with one capacity calculation, then follow the
consequences to nearby islands. Keep an eye on the whole network as the
numbers fill. Each justified bridge makes the final connected solution
easier to see.
Sound Effects Credits
The sound effects used on the game come from multiple parties. The credits and
respective licenses are listed below:
Disclaimer
This game is a property of Lofi and Games. All code and assets are protected and must
not be redistributed or used without prior permission.