What is a palindrome?

A palindrome is a word, phrase, number, or sequence that reads the same forwards and backwards. Classic single-word examples include "racecar", "level", and "madam". Phrases can also be palindromes when punctuation and spaces are ignored — "A man, a plan, a canal: Panama" is one of the most famous examples.

Palindromes appear in mathematics (palindromic numbers like 121 or 1331), biology (palindromic DNA sequences), and recreational linguistics. Detecting them requires normalizing the input — deciding whether to treat uppercase and lowercase letters as the same, and whether spaces or punctuation should count — before comparing the string to its reverse.

Tool description

This tool checks whether a given word or phrase is a palindrome. Paste or type any text, and the tool immediately reports whether it reads the same in both directions. Two options let you control how strictly the check is applied: ignoring letter case and stripping non-alphanumeric characters (spaces, punctuation, hyphens, etc.) before comparing.

Examples

Input Ignore case Ignore non-alphanumeric Result
racecar ✓ ✓ Palindrome
Racecar ✓ ✓ Palindrome
Racecar ✗ ✓ Not a palindrome
A man, a plan, a canal: Panama ✓ ✓ Palindrome
hello ✓ ✓ Not a palindrome
12321 ✓ ✓ Palindrome

Features

  • Real-time palindrome detection as you type
  • Option to ignore letter case for case-insensitive checks
  • Option to strip spaces and punctuation before checking

Options explained

Option Description
Ignore case Treats uppercase and lowercase letters as equal (A = a)
Ignore non-alphanumeric Removes spaces, punctuation, and symbols before comparing, so phrases like "A man, a plan, a canal: Panama" are recognized as palindromes