ArrayList vs LinkedList in Java for Backend Developers

ArrayList vs LinkedList in Java: performance, memory usage, access patterns, backend use cases, and when to choose each List implementation.

By Anderson Alvarez Vásquez · 2026-07-10

• technology
• programming
• tutorials
• Java

ArrayList and LinkedList are two common implementations of the List interface in Java. Both store ordered elements and allow duplicates, but they work very differently internally. For backend developers, the important question is not just what they do, but when each one makes sense in real application code. What Is an ArrayList ? ArrayList stores elements in a dynamic array. java List<String names = new ArrayList< ; names.add "Java" ; names.add "Ruby" ; names.add "PostgreSQL" ; System.out.println names.get 0 ; // Java Use ArrayList when: - You need fast access by index. - You mostly add items at the end. - You iterate over data frequently. - You build API responses. - You process database results. For most backend applications, ArrayList is the default List implementation. What Is a LinkedList ? LinkedList stores elements as nodes. Each node points to the previous and next node. java List<String queue = new LinkedList< ; queue.add "job-1" ; queue.add "job-2" ; queue.add "job-3" ; System.out.println queue.remove 0 ; // job-1 LinkedList can also be used as a queue or deque. java Deque<String jobs = new LinkedList< ; jobs.addLast "send-email" ; jobs.addLast "generate-report" ; System.out.println jobs.removeFirst ; // send-email Use LinkedList when: - You need frequent insertions or removals at the beginning or middle. - You need queue-like behavior. - You rarely access elements by index. - You understand the additional memory cost. In many backend applications, ArrayDeque is a better choice than LinkedList for queue operations. Main Difference The main difference is how data is stored. ArrayList uses a dynamic array: text item0 item1 item2 item3 LinkedList uses linked nodes: text item0 <- item1 <- item2 <- item3 This affects performance, memory usage, and access...