The layout is good, the data returned is accurate. There’s a number of paid subnet calcs out there, and I can’t find any compelling reason to use them when this one is available. The only shortcoming is that it only goes down to a /8. I can’t think of a compelling reason not to just go all the way down to 1. A small quibble.

Indispensable app in my line of work. I contacted the developer through their website and informed them of an issue SubnetCalc and macOS Sequoia. Within an hour they pushed a fix to the GitHub repository and it was available in the app store the next day. I have to say I was super impressed and will be buying you several coffees!

Four tabs--four tasks. This calculator is great for doing the task at hand, and presents the information clearly. However, I think there is a little too much whitespace, especially in the CIDR tab. As a CCNA student, it's a great tool while I try to wrap my head around subnetting, while not getting left behind during lectures.

Does what I need it to do for IPv4. However, please add support for IPv4 multicast subnetting. Furthermore, please allow coping from the fields themselves. For instance I want to copy the subnet ID out. It aggrivates me that I can not do that.