Palindrome Checker

"A man, a plan, a canal: Panama" — check any word, sentence or number, with punctuation and case ignored the way the puzzle intends.

Famous palindromes

Frequently asked questions

Do spaces and punctuation count?

By convention, no — sentence palindromes ignore everything except letters and digits, and ignore case. Tick strict mode if you want a character-exact check instead.

What's the longest single-word palindrome?

In English dictionaries, "tattarrattat" (a knock on the door, coined by James Joyce) at 12 letters; "detartrated" (11) is the longest with a straight face. Finnish beats both with "saippuakivikauppias" — a soapstone seller, 19 letters.

Why do programmers love palindromes?

Reversing a string is a classic first exercise, and "check if it's a palindrome" is a staple interview warm-up — the polished answer skips the copy and compares characters from both ends inward.

Last updated: 2026-07-13