Text & writing
Palindromes: Words That Read the Same Backward
A palindrome reads the same backwards as forwards — “level”, “racecar”, or “A man, a plan, a canal: Panama”. Checking one sounds like a job for text reversal, but phrases need a little preparation first. This guide explains what counts as a palindrome and how to check one.
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Kinds of palindromes
- Words: level, radar, racecar, refer.
- Phrases: “Was it a car or a cat I saw?” and “A man, a plan, a canal: Panama”.
- Numbers: 1221, 12321.
- Word-level palindromes, where the order of words reads the same both ways, are a rarer variety.
Why phrases need preparation
Phrase palindromes only work if you ignore spaces, punctuation, and capitalization. Reversed exactly, “Was it a car” becomes “rac a ti saW”, which does not match. To check a phrase, first remove spaces and punctuation and make everything lowercase, then compare the result with its reverse.
How to check a palindrome
- Make the text lowercase.
- Remove spaces and punctuation.
- Reverse the result.
- If the reversed text is identical to the prepared text, it is a palindrome.
Near relatives
Some words spell a different word when reversed, such as “stressed” and “desserts” or “drawer” and “reward”. These are not palindromes but are sometimes called semordnilaps — “palindromes” spelled backwards.
Palindromes Explained FAQ
- What is a palindrome?
- A word, phrase, or number that reads the same backwards as forwards, such as “level” or 12321.
- Do spaces and punctuation count in a palindrome?
- For phrases, they are usually ignored, along with capitalization.
- How do I check if a sentence is a palindrome?
- Lowercase it, remove spaces and punctuation, then compare it with its reverse.
- What is the word for words that spell another word backwards?
- They are sometimes called semordnilaps, such as “stressed” and “desserts”.
- Can numbers be palindromes?
- Yes. Numbers such as 121 and 1221 read the same in both directions.
Related guides
- Why Reversing Text Breaks EmojiWhy naive text reversal breaks emoji, flags, and accented letters, how grapheme clusters fix it, and how to test a text reverser.
- Reversed, Mirrored, Upside-Down TextThe difference between reversed text, reverse line order, mirrored text, and upside-down text, and how each one is created.
