Visualizers

Insertion Sort Visualizer

Step-through animation of Insertion Sort showing active elements shifting.

native (Canvas API) Client-side

Input Mode

Array Size (10-50)

Speed

Ready to visualize.

Execution Log

Comparisons: 0

Swaps: 0

Current Action:

Idle

Legend:

Unsorted

Active Element

Shifting / Compare

Sorted Subarray

Insertion Sort Algorithm

Insertion Sort is a simple sorting algorithm that builds the final sorted array one item at a time. It is much less efficient on large lists than more advanced algorithms like Quick Sort or Merge Sort.

How It Works

Assume the first element is already sorted.
Pick the next element (key) and compare it with elements in the sorted subarray (from right to left).
Shift all elements that are greater than the key to the right.
Insert the key at the correct index.
Repeat until the array is fully sorted.

Implementation

function insertionSort(arr) {
  const n = arr.length;
  for (let i = 1; i < n; i++) {
    const key = arr[i];
    let j = i - 1;
    while (j >= 0 && arr[j] > key) {
      arr[j + 1] = arr[j];
      j--;
    }
    arr[j + 1] = key;
  }
  return arr;
}

def insertion_sort(arr):
    n = len(arr)
    for i in range(1, n):
        key = arr[i]
        j = i - 1
        while j >= 0 and arr[j] > key:
            arr[j + 1] = arr[j]
            j -= 1
        arr[j + 1] = key
    return arr

public class InsertionSort {
    public static void insertionSort(int[] arr) {
        int n = arr.length;
        for (int i = 1; i < n; i++) {
            int key = arr[i];
            int j = i - 1;
            while (j >= 0 && arr[j] > key) {
                arr[j + 1] = arr[j];
                j--;
            }
            arr[j + 1] = key;
        }
    }
}

#include <vector>

void insertionSort(std::vector<int>& arr) {
    int n = arr.size();
    for (int i = 1; i < n; i++) {
        int key = arr[i];
        int j = i - 1;
        while (j >= 0 && arr[j] > key) {
            arr[j + 1] = arr[j];
            j--;
        }
        arr[j + 1] = key;
    }
}

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