ActiveDNS news

API access, and Subfinder on the way

2026-10-02T00:00:00Z

ActiveDNS now has API access. Instead of copying results from the website, tools can ask ActiveDNS directly with a free API token.

Tokens are self-service: enter your e-mail address on a token page, open the link we send you, and press the button. The token is created and shown once, in your browser. During this beta, tokens are valid for 90 days and come with an hourly and a daily budget, so the service stays free and responsive for everyone. We do not keep your e-mail address, only a keyed hash of it, so we can limit how many tokens one address gets.

The first integration is Subfinder by ProjectDiscovery, the passive subdomain discovery tool. I have written an ActiveDNS source for it and am submitting it to the project. Until it is merged and part of a Subfinder release, Subfinder does not know about ActiveDNS yet, but a token already works with the API directly. You can get one on the Subfinder token page, and the API documentation shows what you can ask.

Feedback on the API, and requests for other tools you would like to see supported, are very welcome through the contact page.

CNAME support

2026-09-29T00:00:00Z

ActiveDNS is now capturing CNAME records and present lookup chains to the user. This allows for a more complete picture of the domain infrastructure, including the ability to trace the origin of a domain name and understand the relationships between different domain names and IP addresses.

Release

2026-09-26T00:00:00Z

After a long time keeping ActiveDNS a tool for myself, friends and colleagues, I've felt it was mature enough to be released to the public. The service is free to use, and the public queries support queries that are not labor intensive on the database.

I hope you will find the service useful for your type of work and would appreciate feedback and any endorsements you can give this website to others.