Free Palindrome Checker
Instantly check if any word, phrase, sentence or number reads the same forwards and backwards. Live detection with letter-by-letter comparison.
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What Is a Palindrome?
A palindrome is a word, phrase, number or sequence of characters that reads exactly the same forwards and backwards. The simplest examples are words like racecar, level, madam and kayak — reverse the letters and you get the same word back.
Palindromes are one of the oldest word games in the world. They appear in graffiti at Pompeii, in medieval Latin verse, and in ancient Chinese and Sanskrit poetry. Today they're a favourite puzzle for writers, programmers and word lovers.
The rules of palindromes
Most palindromes follow a few loose conventions to make them work:
- Ignore case —
Racecarandracecarare both palindromes. - Ignore spaces — "A man a plan a canal panama" becomes
amanaplanacanalpanama. - Ignore punctuation — Commas, apostrophes, hyphens and periods are usually stripped out.
- Ignore accents (optional) —
caféandcafecan be treated the same if you choose.
Our tool lets you toggle each of these rules so you can check text exactly the way you want.
Famous palindrome examples
| Palindrome | Length |
|---|---|
| racecar | 7 |
| madam | 5 |
| level | 5 |
| radar | 5 |
| kayak | 5 |
| deified | 7 |
| reifier | 7 |
| rotator | 7 |
| detartrated | 11 |
| tattarrattat | 12 |
Famous palindromic phrases
- "A man, a plan, a canal, panama." — the most famous palindrome in English (21 letters after cleanup).
- "Was it a car or a cat I saw?" — a classic mirror-sentence (18 letters).
- "Never odd or even." — philosophical palindrome (14 letters).
- "Do geese see God?" — a famous one-word-per-sentence palindrome (13 letters).
- "Murder for a jar of red rum." — a darker classic (19 letters).
- "Step on no pets." — a subtle everyday palindrome (11 letters).
- "Mr. Owl ate my metal worm." — modern internet palindrome (16 letters).
- "A Santa lived as a devil at NASA." — a popular NASA-themed palindrome (23 letters).
Palindromic numbers
Numbers can be palindromes too. Anything that reads the same forwards and backwards counts — including single digits (0–9), and longer numbers like 11, 121, 1221, 9009, 12321, 1234321.
Some interesting number palindrome facts:
- Palindromic primes — prime numbers that are also palindromes: 2, 3, 5, 7, 11, 101, 131, 151, 181, 191…
- Reverse-and-add chains — take any number, reverse it, add the two; repeat. Most numbers eventually produce a palindrome. 195 is the smallest known number that may never reach one (a "Lychrel number").
- Palindromic dates — dates like 2/2/2020 (a palindrome in MM/DD/YYYY format) fascinate number nerds.
How our palindrome checker works
- Clean the input. Depending on your toggles, we lowercase the text and strip spaces, punctuation and accents.
- Reverse the cleaned string. We flip the characters end-to-end.
- Compare character by character. We walk forward through the cleaned text and backward through the reversed version, matching at each step.
- Report the result. If every character matches, it's a palindrome. If not, we highlight exactly where the mismatch happens.
Palindrome vs anagram vs ambigram
These three wordplay categories are often confused. Here's the difference:
- Palindrome — reads the same forwards and backwards. Order is preserved; the symmetry is in the letters themselves. Example:
level. - Anagram — a rearrangement of the letters of a word or phrase to form a different word or phrase. Order changes. Example:
listen→silent. - Ambigram — a word or design that looks the same when rotated 180° or viewed in a mirror. Example:
SWIMSrotated upside-down still readsSWIMS.
Common use cases
- Puzzles and word games — verify palindromes while solving crosswords or anagram puzzles.
- Programming challenges — test your solution against expected results before submitting to LeetCode or HackerRank.
- Teaching — demonstrate string manipulation, loops and comparison logic with a simple, engaging example.
- Creative writing — craft palindromic poetry, palindromic haikus, or "palindrome chains".
- Number theory — verify whether integers are palindromic in a given base (decimal, binary, hex).
Privacy and security
This palindrome checker runs entirely in your browser. Your text is never sent to any server, never stored anywhere, and disappears the moment you close the tab. Safe for confidential text, private notes and any content you want to keep local.
Frequently Asked Questions
What is a palindrome?
racecar, madam, level and A man, a plan, a canal, panama. Palindromes ignore spaces, punctuation and usually case.What is the longest palindrome?
tattarrattat (12 letters), coined by James Joyce in Ulysses. The longest palindromic sentence is "A man, a plan, a canal, panama" at 21 letters after cleanup. There are much longer constructed palindromes, but they are artificial.Do palindromes ignore spaces and punctuation?
Madam and madam are treated the same. Our tool lets you toggle each of these rules.Are numbers palindromes?
121, 12321, 1221 and 9009 are palindromes. Some fascinating numerical properties involve palindromes, like Lychrel numbers, reverse-and-add chains, and palindromic primes.What is the difference between a palindrome and an anagram?
listen and silent are anagrams; level is a palindrome.Is this palindrome checker case sensitive?
Racecar and racecar both count as palindromes. You can toggle "Ignore case" off to require exact case matches on both sides.Can palindromes contain spaces?
amanaplanacanalpanama becomes a valid palindrome. This is a standard convention in palindrome checking.