I threw together this tool (took about 15 minutes to make) for a related post about filtering traffic by IP address in Google Analytics views. Excluding multiple IP addresses at the same time with a single filter in GA is only possible by using a custom IP address filter pattern, which uses regular expression pattern matching. This tool is for those that want to quickly generate a regex pattern to use based on a list of IP addresses.
Simply paste your list of addresses into the left box, and than copy the generated pattern from the right box and paste right into your new Google Analytics filter!
Click the “Demo” button to see an example. You can validate results using this tool.
The code behind this tool can be found here.