This online calculator filters lines of text by removing designated lines or, you can say, leaving only designated lines

This online calculator can be used to summarize lines of text, using regular expressions to extract a unique value from each line, such as a date or session ID.

The calculator takes a list of URLs as input and extracts the domain name part from each URL. It then counts the number of occurrences for each unique domain name and displays the results in descending order.