Sorting

Bubble sort vs Insertion sort

Bubble sort and Insertion sort both put an array in order, in different ways. Bubble sort: swap neighbors that are out of order. Insertion sort: insert each value into a sorted prefix. In the worst case both take O(n²), so the choice comes down to the other differences below.

At a glance

Property	Bubble sort	Insertion sort
Technique	Swap neighbors that are out of order	Insert each value into a sorted prefix
Best case time	O(n)	O(n)
Average case time	O(n²)	O(n²)
Worst case time	O(n²)	O(n²)
Extra space	O(1)	O(1)
Stable (equal values keep their order)	Yes	Yes
In place (no extra array)	Yes	Yes
Needs sorted input	No	No

Choose bubble sort when

you want the simplest sort to explain, on tiny or almost sorted data.

Avoid it when

the data is large.

Choose insertion sort when

the array is small or nearly sorted.

Avoid it when

the array is large and in random order.

The same inputs, counted

These numbers come from running both real implementations: operations (comparisons plus writes, a swap counting as two writes).

Input	Bubble sort	Insertion sort
Mixed	40	30
Already sorted	6	12
Reversed	63	48
Nearly sorted	13	14
Duplicates	47	36

Bubble sort vs Insertion sort

At a glance

Choose bubble sort when

Avoid it when

Choose insertion sort when

Avoid it when

The same inputs, counted

See them run

More comparisons

Bubble sort vs Insertion sort

At a glance

When to choose each

Choose bubble sort when

Avoid it when

Choose insertion sort when

Avoid it when

The same inputs, counted

See them run

More comparisons