Stack Visualizer (LIFO)
Push / pop / peek / clear on a last-in-first-out stack, with per-step animation and a use-case walkthrough.
LIFO — Last In, First Out. The most recently pushed element is always the first one removed.
Stack
Top ↑
— base / bottom —
Type any value and Push to drop it onto the top of the stack; Pop removes and returns the top element; Peek shows the top without removing it; Clear empties the stack. The column is drawn bottom-up so the newest element is always on top. Size shows the number of elements, Top shows the most recently pushed value, and the step log records every operation with timestamps. Stacks power bracket matching in parsers, undo/redo history, and the call stack that tracks function invocations — three scenarios explained below.
Where stacks are used
Three classic, everyday applications of the LIFO principle.
Bracket matching
Compilers push every opening bracket and pop on its closing pair to verify they nest correctly — a stack is the natural fit.
Undo / history
Editors push each action onto a stack; Undo pops the latest action and reapplies its reverse — most recent first, exactly LIFO.
Function call stack
Every function call pushes a frame onto the call stack; returning pops it. Recursion works because the deepest call resolves first.