Advanced PortChecker is a free and open-source application that can help you check if ports are open or closed on a certain host. You can check multiple ports at once and export the results in plain text, CSV or JSON format!
Screenshots

Install
If this does not work, see FAQ#1
If this button doesn't work, see FAQ #1
How to install?
Screenshots
Sites
Sources
Exact match
Name match
Description match
No applications found
No applications found matching "{0}"
Try selecting "All architectures" or broadening your search keywords.
Check for typos or try searching with different keywords.
Clear search
{0} results
Failed to load apps.