Free
CIDR and subnet calculator
Address range, the hosts AWS leaves usable, subnet splits, and overlap checks between two blocks.
Tools
Small checks for AWS work. No sign-in needed.
Address range, the hosts AWS leaves usable, subnet splits, and overlap checks between two blocks.
Flags wildcard actions, wildcard resources, public principals, and broad statements with no Condition.
Finds SSH, RDP, and database ports open to the internet, all-traffic rules, wide port ranges, and duplicate rules.