Setting a cutoff for string distance filtering with different length strings I'm working to filter a table of pairwise names (1.1 M rows) based on string distance algorithms. Most are names, though some are businesses.

Edit-based algorithms seem to be best, however in attempting to set a cutoff value for match vs. non-match, there is an issue with the length of the string.  In a 16 character string, a score of 4 is usually a good match.  But of course in a 4 character string, a score of 4 is a complete non-match.

What are good options for using a string distance algorithm, but scaling the scores relative to the length of the comparison strings? This doesn't seem to be built into any of the algorithms I've found.
You can use normalized edit distance, where you divide the edit distance by the length of the larger of the two strings.  Whether this is better will depend on what you are trying to achieve.

There are many other techniques for fuzzy matching, which you might want to investigate.  The Levenshtein edit distance is only a starting point.