VMHeaven tools
Free network and server tools
The small things you look up while setting up a server — a subnet, a file mode, a cron schedule, a DNS record or your own address. Free, without an account, and without ads.
Calculators and generators
They run in your browser; nothing you type is sent anywhere.
- Subnet calculatorNetwork, broadcast, netmask, wildcard and host range for any IPv4 or IPv6 prefix, with subnet splits.Open tool
- Chmod calculatorLinux file permissions between octal (755) and symbolic (rwxr-xr-x), with setuid, setgid, sticky and chmod commands.Open tool
- Cron expression generatorBuild a crontab schedule, read it in plain English and see the next run times in your time zone or in UTC.Open tool
Network checks
Answered by our server: DNS questions go to public resolvers, and the IP check only ever looks at your own address.
What the tools do with your input
The calculators keep everything in your browser. The DNS tools send the name you enter to public resolvers and nothing else. The IP check reads your address from the request, never from a form, and none of the tools stores what you look up.
More to read
Step-by-step fixes and setup guides for Linux and Windows servers are on the VMHeaven blog.