Palindrome Checker
Check a word, name or sentence for a palindrome, and see the longest palindrome hidden inside a longer piece of text.
Este contenido está en inglés.
Your text, with the longest palindrome highlighted
Ejemplos resueltos
Checking a famous phrase
A man, a plan, a canal: Panama, with both options on
Palindrome: yes
With both options on, capital letters, spaces and punctuation are ignored, so the phrase reads the same backwards.
Finding the longest palindrome
racecarxyz, with the longest palindrome option on
Longest palindrome: racecar (7 characters)
A single letter always counts as a palindrome, so the longest one is never shorter than one character.
Sobre Palindrome Checker
A palindrome is a word, number or phrase that reads the same forwards and backwards, such as level, 1221 or the famous phrase A man, a plan, a canal: Panama. This palindrome checker tells you whether your text is one, and it can ignore capital letters, spaces and punctuation so that phrases with normal spacing are judged fairly. Switch both options off and every character is compared exactly as typed, which is useful for codes, serial numbers and any case where spacing matters.
The tool also finds the longest palindrome inside a longer piece of text. A long sentence or an essay can contain a hidden palindrome of several characters, and the tool locates the longest one and highlights it in your text so you can see exactly where it is. Ties are resolved by showing the first palindrome of the longest length. The search is quick even for long passages, so you can paste a whole paragraph and get the answer straight away.
Cómo usar Palindrome Checker
- Type or paste the text you want to check into the box.
- Leave Ignore capital letters and Ignore spaces and punctuation ticked for phrases, or untick them to compare every character.
- Read the verdict to see whether the whole text is a palindrome.
- Look at the highlighted text to see the longest palindrome it contains, and its length.
Usos habituales
- Checking a famous phrase or a name for a crossword or word game
- Finding a palindrome hidden inside a poem, lyric or essay
- Testing number palindromes such as 12321 for a maths activity
- Preparing puzzles, quizzes and classroom starter tasks
Preguntas frecuentes
What is a palindrome?
A palindrome is a sequence of characters that reads the same backwards as forwards. Words such as racecar and level are palindromes, and so are numbers such as 1001. Phrases can also be palindromes when spaces, capital letters and punctuation are ignored, which is why A man, a plan, a canal: Panama is counted as one.
Why do capital letters and punctuation matter?
They change the result when the options are off. Racecar is not a palindrome if you compare the capital R with the lower case r at the end, but it is one when capitals are ignored. Likewise, a phrase with commas and spaces is only a palindrome when those marks are left out. With both options on, the tool compares just the letters and numbers, which is how most people judge a phrase.
What does the longest palindrome mean?
The longest palindrome is the longest run of consecutive characters in your text that reads the same forwards and backwards. It may be a single word, part of a word or several words. The tool highlights it in the full text, so you can see where it sits. A single character always counts as a palindrome, so the result is never shorter than one.
Can the checker handle very long texts?
Yes. The longest palindrome search runs in a single pass over the text, so it stays quick even for several pages of writing. The result shows the original text with the palindrome highlighted, so long passages are easy to scan. For the most useful answer, paste the passage you are interested in rather than an entire book.
Are numbers checked as well?
Yes. Digits are treated like letters, so 1221, 12321 and 9009 are all palindromes. You can mix numbers and words too, for example a code such as A1B1A is a palindrome when capitals are ignored. Turn off the option that ignores punctuation if you want dashes or slashes to count as characters in the comparison.