Floyd Warshall Visualizer

Paste directed weighted edges, then step through the all-pairs shortest path matrix as Floyd-Warshall tests each intermediate node.

Nodes
5
Edges
9
Updates
0
Distance
8

Directed graph input

Use one directed edge per line: source, target, weight. The matrix keeps up to 8 nodes.

Step controls

Initialize the matrix with direct edge weights and zero on the diagonal.

All-pairs distance matrix

Rows are sources and columns are targets. Blue is the cell being improved.

via k i-k or k-j cycle
from/toABCDE
A038inf-4
Binf0inf17
Cinf40infinf
D2inf-50inf
Einfinfinf60

Current relaxation

k = -
i = -
j = -
updates = 0

Selected path output

source = A
target = C
distance = 8
path = A -> C

What is a Floyd Warshall Visualizer?

A Floyd Warshall visualizer shows how all-pairs shortest paths are improved by allowing each node to act as an intermediate waypoint. It is useful for learning dynamic programming on graphs, transitive closure ideas, weighted adjacency matrices, and shortest-path interview problems.

This tool lets you paste directed weighted edges, choose a source and target pair, then step through the distance matrix as every i -> k -> j candidate is considered.

For the full graph and data structure set, browse the Data Structure Visualizers hub.

How to use this Floyd Warshall visualizer

  • Paste one directed weighted edge per line, such as A B 3.
  • Enter the source and target pair you want to inspect.
  • Click Run Floyd-Warshall to jump to the final all-pairs matrix.
  • Step through each intermediate node to see which distances improve.
  • Read the matrix cell for any shortest path from row node to column node.

Floyd Warshall vs Bellman Ford

Bellman-Ford solves shortest paths from one start node and can detect reachable negative cycles. Floyd-Warshall solves shortest paths between every pair of nodes in one dynamic programming table, and it can reveal negative cycles when a diagonal distance becomes negative.

Compare this page with the Bellman Ford Visualizer for single-source negative-edge search and the Dijkstra Algorithm Visualizer for non-negative weighted graphs.

Frequently Asked Questions

What input format does this Floyd Warshall visualizer use?
Paste one directed weighted edge per line with source, target, and weight, such as A B 3 or A -> C -4.
Does Floyd-Warshall support negative weights?
Yes. Floyd-Warshall supports negative edge weights, but a negative cycle makes shortest paths undefined for affected pairs.
How does this tool show negative cycles?
After the matrix is complete, the tool marks any node whose diagonal distance is negative. A negative diagonal means a negative cycle is reachable from that node back to itself.
When should I use Floyd-Warshall?
Use Floyd-Warshall when the graph is small enough for O(V^3) work and you need shortest paths between many or all node pairs.

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