Bubble Sort

2026-05-02

Written by: Juri Breslauer

Algorithm Notes

Bubble sort, one neighbor at a time

Bubble sort compares two neighboring values. If the left value is bigger, they swap places. After each pass, the largest unsorted value has moved to the right side.

Interactive demo

15 bars bubble sort

Ready

Pass 1

Compare 0

Swaps 0

Why It Looks Like This

The animation uses exactly 15 bars. On every step, bubble sort looks at two neighbors:

If the left bar is taller, the bars swap.
If the left bar is smaller, the algorithm moves on.
At the end of a pass, one more bar on the right is already in its final place.

Complexity

Bubble sort is easy to understand, but it is not efficient for large inputs. In the average and worst case it needs O(n²) comparisons. For 15 bars that is fine for a visual demo. For thousands of items, a better sorting algorithm is usually the right choice.

Here are examples of the same bubble sort algorithm in different programming languages.