Palindrome Checker
Type any word or phrase and instantly check if it's a palindrome. Spaces, punctuation, and capitalisation are ignored.
Spaces, punctuation, and capitalisation are ignored.
It's a Palindrome!
“A man a plan a canal Panama” reads the same forwards and backwards.
Character comparison
Cleaned string (21 chars): amanaplanacanalpanama
Quick examples
Frequently Asked Questions
What is a palindrome?
A palindrome is a word, phrase, or sequence that reads the same forwards and backwards. Examples include 'racecar', 'level', and 'A man a plan a canal Panama'.
Does the checker ignore spaces and punctuation?
Yes. The checker strips all non-alphanumeric characters and converts to lowercase before comparing. This means 'A man, a plan, a canal: Panama' correctly detects as a palindrome.
What does the character comparison view show?
It shows the cleaned string (letters only, lowercase) aligned with its reversed version. Characters that match are highlighted green; mismatches are highlighted red.
Is the check case-sensitive?
No. The comparison is always case-insensitive. 'Racecar' and 'RACECAR' are both detected as palindromes.
What is the longest palindrome ever found?
Famous long palindromes include 'A man, a plan, a canal: Panama' (21 letters) and the 224-word poem by Leigh Mercer. The checker handles any length of text.
What Is a Palindrome?
A palindrome is a word, phrase, or number that reads the same forwards and backwards after ignoring capitalisation, spaces, and punctuation. The name comes from the Greek palindromos — “running back again”.
How the Check Works
- Normalise — convert to lowercase and strip all non-alphanumeric characters.
- Reverse — create the reversed version of the cleaned string.
- Compare — if the normalised string equals its reverse, it's a palindrome.
// "A man, a plan, a canal: Panama" cleaned = "amanaplanacanalpanama" reversed = "amanaplanacanalpanama" // ✓ palindrome
Famous Palindromes
- “A man, a plan, a canal: Panama”
- “Was it a car or a cat I saw?”
- “Never odd or even”
- “Madam, I'm Adam”
- “Do geese see God?”