Difference between append() and extend() in Python

Last Updated : 13 Jan, 2026

append() and extend() are two list methods used to add elements to a list, but they behave differently.

append() adds a single item (of any type) to the end of a list.
extend() adds all elements from an iterable (like a list, tuple, or set) to the end of the current list.

append() Method

append() method adds a single element to the end of a list. This element can be a number, string, list, or any object.

Syntax:

list.append(element)

👁 file

List.append

Output

['geeks', 'for', 'geeks']
['geeks', 'for', 'geeks', ['a', 'coding', 'platform']]

extend() Method

extend() method adds all elements from an iterable to the end of the current list. Unlike append(), it does not add the iterable as a single element; instead, each element is added individually.

Syntax:

list.extend(iterable)

👁 file

List.extend

Output

['geeks', 'for', 6, 0, 4, 1]

Note: A string is also an iterable, so if we extend a list with a string, each character of the string is appended individually.

Key Difference Between append() and extend()

Feature	`append()`	`extend()`
Purpose	Adds a single element to the end of the list.	Adds multiple elements from an iterable to the end of the list.
Argument Type	Accepts a single element (any data type).	Accepts an iterable (e.g., list, tuple).
Resulting List	Length increases by 1.	Length increases by the number of elements in the iterable.
Use Case	When we want to add one item.	When we want to merge another iterable into the list.
Time Complexity	O(1) , as adding a single element is a constant-time operation.	O(k), where k is the number of elements in `b`