String Similarity Checker: Levenshtein, Dice, Jaro-Winkler, LCS

A string similarity checker that compares two pieces of text four different ways at once, so you can pick the number that actually fits your problem. It computes the Levenshtein edit distance (the count of single-character inserts, deletes and substitutions to turn one string into the other) and turns it into a normalized 0-100% score. Next to that it shows the Dice coefficient, which measures overlapping character bigrams and is forgiving of word order, the Jaro-Winkler similarity, which rewards matching prefixes and is the go-to metric for names and short labels, and the longest common subsequence length. Two toggles let you decide whether case and whitespace count, and every result comes with a one-line explanation plus a worked example so you are never staring at a bare number. Everything runs as plain JavaScript in your tab, handles Unicode by code point so emoji and CJK characters count correctly, and the share link reproduces both inputs and your exact settings. No upload, no account, no rate limit.