How to compare two NumPy arrays?

Last Updated : 19 Sep, 2025

Sometimes you need to check if two arrays are same or compare their values. NumPy provides multiple ways to do this from simple equality checks to element-wise comparisons. Comparing arrays helps in:

  • Validating data correctness
  • Checking results of operations
  • Filtering or selecting data based on conditions

Let’s explore different methods to compare two arrays.

Using np.array_equal()

The array_equal() function is the simplest and most reliable way to compare two arrays. It checks whether:

  • Both arrays have the same shape
  • All elements are exactly the same

Syntax:

numpy.array_equal(arr1, arr2)

Example: This code compares two arrays using np.array_equal() and prints whether they are equal.

Python 
import numpy as np

arr1 = np.array([[1, 2], [3, 4]])
arr2 = np.array([[1, 2], [3, 4]])

if np.array_equal(arr1, arr2):
    print("Equal")
else:
    print("Not Equal")

Output
Equal

Explanation: np.array_equal() returns True if arrays have the same elements and shape. It’s the cleanest and most reliable way to check equality.

Using == and .all()

This method first compares arrays element-wise using ==, then checks if all results are True with .all().

Example: This code uses element-wise comparison followed by .all() to decide if two arrays are fully equal.

Python 
import numpy as np

arr1 = np.array([[1, 2], [3, 4]])
arr2 = np.array([[1, 2], [3, 4]])

dif = arr1 == arr2
b = dif.all()
print(b)

Output
True

Explanation: Every element matches, so result is True. If even one element was different, it would return False.

Using Comparison Operators (>, <, >=, <=)

This method is not for equality checks, but for comparing values element by element. It helps when you want to know which array elements are greater/smaller.

Example: This code compares two arrays element by element using greater/less operators.

Python 
import numpy as np

a = np.array([101, 99, 87])
b = np.array([897, 97, 111])

print("Array a:", a)
print("Array b:", b)

print("a > b:", np.greater(a, b))        
print("a >= b:", np.greater_equal(a, b)) 
print("a < b:", np.less(a, b))           
print("a <= b:", np.less_equal(a, b))

Output
Array a: [101  99  87]
Array b: [897  97 111]
a > b: [False  True False]
a >= b: [False  True False]
a < b: [ True False  True]
a <= b: [ True False  True]

Explanation: The result is a Boolean array, where each element shows the comparison result at that position. This is useful for conditional checks, not equality.

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