Free developer tools

Fast, single-purpose network tools built by the BookMyHost engineering team for our own day-to-day work: no sign-up, no ads, each with a JSON API.

DNS Propagation Checker

Check whether your DNS record has propagated to public resolvers worldwide, including India.

CIDR calculator with network, broadcast, usable range, wildcard, binary, split and supernet.

Measure DNS, TCP, TLS, time to first byte and inspect the SSL certificate of any site.

Every tool is also an endpoint under /tools/api/v1/ with OpenAPI docs at /tools/api/v1/docs. Limit: 30 requests per minute per IP.

curl -s -X POST https://bookmyhost.com/tools/api/v1/subnet/calc -H 'Content-Type: application/json' -d '{"cidr":"10.0.0.0/22"}'

Are these developer tools free?

Yes. Every tool here is free, needs no sign-up and has a public JSON API. They are built and run by the BookMyHost engineering team.

Can I link to or embed a tool?

Yes, please do. Each tool page has a ready-made HTML snippet you can paste into docs, blogs or internal wikis.