Palindrome checker
This tool checks whether words and phrases read the same forward and backward. Students, puzzle makers and programmers use it to test palindromes like racecar and to find the longest palindrome hidden in a line.
- Runs in your browser
- Free, no account needed
- Copy or download the result
Result
Example
A man, a plan, a canal: Panama racecar Palindrome Never odd or even
Palindromes: 3 of 4 lines checked Line 1: Yes "A man, a plan, a canal: Panama" compared as: amanaplanacanalpanama Line 2: Yes "racecar" compared as: racecar Line 3: No "Palindrome" compared as: palindrome Line 4: Yes "Never odd or even" compared as: neveroddoreven Longest palindrome inside the text: "A man, a plan, a canal: Panama" (line 1, 21 characters compared)
How to use the palindrome checker
- Type words or phrases, one per line, into the box.
- Choose whether to ignore case, spaces and punctuation.
- Press Run.
- Read the Yes or No for each line and the longest palindrome found.
How it works
Each line is checked on its own. The result shows the compared form, which is the line after the ignore options are applied.
The longest palindrome search uses the same options and shows the matching part of your original text, including its spaces and punctuation.
Characters are compared as visible characters, so accented letters and emoji are not split.
Input is limited to 100,000 characters and 2,000 lines. Lines with nothing left to compare are skipped.
Everything runs in your browser. Your input is not uploaded or stored.
Questions and answers
What is a palindrome?
A palindrome is a word, number or phrase that reads the same backward as forward, such as level, 12321 or Never odd or even.
Is A man, a plan, a canal: Panama a palindrome?
Yes, when case, spaces and punctuation are ignored, which are the default settings.
Can it find palindromes inside a sentence?
Yes. It reports the longest palindrome found inside any line, such as racecar in I saw a racecar.