Palindrome Checker

Is your word or phrase a palindrome? Use this free online palindrome checker

This free online palindrome checker tells you whether a word, phrase, sentence or number reads the same forwards and backwards. Type it into the box, press the Check button, and the tool answers yes or no and shows the cleaned text it compared. Case, spaces and punctuation are ignored, and everything runs in your browser, so nothing is uploaded.

What does the Palindrome Checker do and why is it useful?

A palindrome is text that reads the same in both directions. Single words such as level and racecar are the classic examples, but whole sentences can qualify too once you ignore spaces, capital letters and punctuation. Numbers can be palindromes as well, for example 12321.

Checking by eye works for short words, but it is slow and error-prone for long phrases, because spaces and commas make the mirror hard to see. The tool strips all of that away and does the comparison for you, then shows its working so you can see exactly what was compared. It is handy for puzzles, word games, classroom exercises, coding practice and curiosity.

How does the palindrome checker work under the hood?

The tool has one text input and one button. When you press Check, it follows a simple procedure:

1. The text is converted to lowercase, so capital and small letters are treated alike.
2. Every character other than the letters a to z and the digits 0 to 9 is removed. That includes spaces, punctuation, symbols and accented letters.
3. The remaining characters, called the cleaned text, are compared with the same characters written in reverse order.
4. If both are identical, the answer is yes. Otherwise it is no.

The cleaned text is displayed alongside the answer, so you can verify the comparison. Because digits are kept, the same procedure works for numbers. Nothing is computed until you press the button, and there is no live updating as you type.

How do you use the tool step by step?

1. Type or paste a word, phrase or number into the text input.
2. Press the Check button.
3. Read the yes or no answer.
4. Look at the cleaned text shown by the tool to see what was compared.
5. Edit your input and press Check again to test another one.

What do real results look like? Worked examples

Example 1: a single word

Input: racecar

Cleaned text: racecar. Reversed: racecar. Answer: yes.

Example 2: a famous sentence

Input: A man, a plan, a canal: Panama

Cleaned text: amanaplanacanalpanama. Reading it backwards gives the same string. Answer: yes.

Example 3: a question

Input: Was it a car or a cat I saw?

Cleaned text: wasitacaroracatisaw. Answer: yes. The question mark and the capital letters made no difference.

Example 4: an apostrophe

Input: Madam, I'm Adam

Cleaned text: madamimadam. Answer: yes. The apostrophe and comma are removed before comparing.

Example 5: not a palindrome

Input: Hello

Cleaned text: hello. Reversed it would be olleh. Answer: no.

Example 6: numbers

Input: 12321. Cleaned text: 12321. Answer: yes.

Input: 12345. Cleaned text: 12345. Reversed it would be 54321. Answer: no.

Example 7: a time with a colon

Input: 10:01

Cleaned text: 1001. Answer: yes. The colon is removed, and the digits read the same in both directions.

Example 8: a phrase with mixed punctuation

Input: No lemon, no melon

Cleaned text: nolemonnomelon. Answer: yes.

What kinds of palindromes can you test?

There are three common kinds, and the tool handles all of them with the same procedure. The first is the single word, such as level or racecar. The second is the phrase or sentence, where the mirror only appears once spaces, punctuation and capital letters are set aside. The third is the number, where the digits mirror each other, as in 12321.

A useful way to think about a sentence palindrome is that it does not need the words to mirror each other. In No lemon, no melon the words are not a mirror of one another, but the letters are. The cleaned text makes this obvious, and it is the reason the tool shows it.

Tips and best practices

• Type the phrase naturally, with spaces and punctuation. There is no need to clean it yourself, because the tool does that and shows the cleaned version.
• Always glance at the cleaned text. It is the quickest way to understand a surprising answer, such as a missing letter.
• To see what a phrase looks like reversed, use the text reverser. The checker only answers yes or no, while the reverser shows the flipped text.
• If you are testing a long text, the character counter can tell you how many letters and digits it contains, which helps when building your own palindromes.
• Use the tool for number puzzles, such as dates or reference codes. Dates written without separators are easy to test, and a random number generator can supply numbers to try.
• Challenge yourself to build longer palindromes and use the checker as an instant referee.

Common mistakes to avoid

• Forgetting to press the button. The answer appears only after you press Check. Editing the input does not refresh it.
• Expecting accented letters to count. Only a to z and 0 to 9 are kept. A letter such as an accented e is removed, which can change the result.
• Thinking spaces matter. They do not. The phrase is compared without spaces, so a phrase can be a palindrome even if the words do not mirror each other.
• Counting punctuation as part of the text. Commas, apostrophes and question marks are ignored on purpose.
• Assuming words in other alphabets are supported. Letters outside a to z are dropped, so text in other scripts will leave little or nothing to compare.

A note on accents and other alphabets

The rule that only a to z and 0 to 9 are kept has a visible effect on non-English text. Take the French word Été, written with accented capital and lowercase e at the start and end. Both accented letters are removed, leaving only t as the cleaned text. That single character reads the same both ways, but the result tells you nothing about the original word. When a phrase contains accented letters, read the cleaned text before trusting the answer.

The same applies to emoji and to alphabets such as Greek, Cyrillic or Arabic. For these, the tool is not a reliable judge of palindromes, and it does not claim to be.

Who uses a palindrome checker?

Teachers use it for spelling games and language lessons. Students of computing use it to check the output of their own palindrome programs. Puzzle fans use it to test candidate phrases, and writers who like wordplay use it to verify clever sentences. Parents and children use it for fun on word days. Anyone curious about whether a name, a date or a license-plate style number mirrors itself can get an answer straight away.

Is my text private?

Yes. The check runs in your browser. What you type is not uploaded to a server and is not stored by the tool. Close or reload the page and it is gone. There is nothing to sign in to and no history to clear.

What are the limitations?

• The answer appears only after you press Check. There is no live updating.
• Only a to z and 0 to 9 are compared. Accented letters, symbols and other alphabets are removed.
• The tool checks a single text input. It does not find the longest palindrome inside a text or list palindromes.
• It has no copy button, file upload or history.

Frequently asked questions

What is a palindrome?

It is a word, phrase or number that reads the same forwards and backwards. Sentences usually count once spaces, punctuation and case are ignored.

Does capitalisation matter?

No. The text is lowercased before it is compared.

Are spaces and punctuation ignored?

Yes. Only the letters a to z and digits 0 to 9 are kept.

Can it check numbers?

Yes. Digits are kept, so 12321 is a palindrome and 12345 is not.

Why does the tool show the cleaned text?

So you can see exactly what was compared and understand the answer.

Why did my accented word give a strange result?

Accented letters are outside a to z, so they are removed before the comparison.

Is a single character a palindrome?

A single character reads the same in both directions, so by the comparison rule the cleaned text would match its reverse. The result is not very meaningful, though.

Mirror words in one click

Whether you are testing a puzzle, a lesson or a line of code, the palindrome checker gives a quick answer and shows how it got there. For more small helpers, browse our free tools.