Palindrome Checker

Check if any word, phrase, or number is a palindrome with options to ignore case, spaces, and punctuation.

Options

Type some text on the left to check whether it's a palindrome

Palindrome Checker

A palindrome is a word, phrase, number, or sequence of characters that reads the same forwards and backwards. Classic examples include 'racecar', 'madam', and the phrase 'A man, a plan, a canal: Panama'. This tool lets you verify any text instantly, with flexible options to ignore case differences, whitespace, and punctuation — so you can check both strict and relaxed palindromes.

Under the hood, the checker normalizes your input according to the selected options (lowercasing, stripping spaces and/or punctuation), then compares the result with its reverse. Both the normalized form and the reversed string are displayed side by side so you can see exactly how the comparison is made — useful for learning, word games, linguistic analysis, and coding exercises.

How it works

Normalize the input string S by applying the selected filters (lowercase, remove spaces, remove punctuation). Then check: isPalindrome = (S === S.split('').reverse().join('')). Time complexity: O(n) where n is the length of the normalized string.

Use cases

  • Verifying palindromic words and phrases for word games or trivia
  • Teaching string manipulation and reversal concepts in programming courses
  • Checking whether numeric sequences or dates are palindromes
  • Validating palindromic DNA sequences in bioinformatics exercises
  • Creating and testing palindrome poetry or constrained writing challenges

Related Calculators