A palindrome reads identically forwards and backwards. This checker normalises your input first — folding case and stripping spaces and punctuation — so classic phrases such as 'A man, a plan, a canal: Panama' and 'Was it a car or a cat I saw?' are correctly identified, not just single words like level or racecar. The same test works on numbers, which is useful when practising the interview-standard palindrome problem or checking numeric IDs. The tool shows the reversed string next to the original so you can see exactly where a near-miss breaks, and it handles multi-line input by testing the whole block as one sequence.
Free, fast, and runs entirely in your browser — no signup, no upload to a server.